Chapter 1

Author's Note: 25/11/23 Hello All, this is the final edit of this chapter (98 to go). Hope you enjoy!

-Prologue-

His eyes opened, the same sterile tiled ceiling he'd stared at for uncountable miserable hours for months on end came into view.

He was tired…so, so tired.

He closed his eyes momentarily, attempting to clear the foggy nature of his mind with only a small measure of success before he tilted his head as he opened his eyes, towards the source of light that was shining through the blinds.

Another day, one less day…

He tore off the bed covers and pulled himself up, with some difficulty, until he managed to get upright, the growing headache that hammered him suddenly causing him to clench tightly on the duvet.

He waited until it passed, until it grew dim and he got to his feet, languidly, and walked past his slippers with his bare foot, uncaring and unwilling to bother even that far as he walked towards the bathroom.

He avoided looking at himself in the mirror, an act he did each time, as he brushed his teeth, and cleaned and dried his face, yet each time he failed not to look.

And each time, a small piece of him grew darker, more broken as the face stared back at him, a face he was ever getting harder and harder reconciling with.

An emaciated face stared back at him, a pallid sheen to a dark skin that could not hide how ill he looked, sunken in cheeks with tight skin rubbed over his skull highlighted how starved he was with how gaunt he looked.

He was little better than a walking skeleton and the lack of hair only added to that visage, something he lost months ago.

It's been two years since he was diagnosed with Glioblastoma at sixteen. Two years since he found out that he had an expiry date of at most two and a half years.

Six months since he became a permanent resident in this hospital, where he was made comfortable, waiting to die, waiting to hit his expiry date.

He'd laughed when he sat in that comfortable office chair after he'd been given his prognosis, bowled over with hysterical laughter, the very visage of the Comedian at that moment.

It had been all a joke then.

It still was a joke now though he wasn't laughing now.

He hadn't the energy.

It had been par for the course he had thought then.

His life had never been easy, his early years had prepared him well for it. 

He sighed, closed his eyes briefly before he toddled out of the bathroom, his bony heels distinctly clanking on the hard floor.

He'd been born to a poor working class family to two people who should never have been parents. His father a violent bitter man, his mother neglectful and meek, unwilling to stand up for any of the abuse that had been heaped on them, on him.

He walked towards the window and with some effort opened it up. 

His room overlooked a small park that was at the centre of the hospital. It was tasteful, a small bit of nature amidst buildings where most things were sterile and severe. 

He sat on the edge of the windows and watched as he saw an old woman shuffling, slowly, along the path of the small park towards one of the benches in front of a small pond where birds tended to be at this early hour. 

There was peace in watching animals in nature, however manufactured it may be.

Peace he ironically began to feel at the end of his short life rather than at any during his life before his body's betrayal.

His early childhood lacked such peace to say the least. It had been horrid, filled with bitter pain and harsh understandings of his lot in life.

Only his books had been able to provide a measure of peace, a measure of joy that came into existence after being taught by an old woman who took pity on him taught him how to read before he was old enough for Primary school.

He'd found what he'd looked for in his books that life at that time did not give, an escape that had him become enamoured and lost in the stories and the pictures in the stories.

Though those were not the memories he clung onto. The children's books that were happy and showed wondrous things, no…

What he had clung onto was the book she'd given him by mistake, a book for adults but one that changed his life. A book he'd read every year since.

It was nothing special, a book written by an author none remembered, a book that sold less than a couple of thousand copies in the thirty years it had been published yet it was his most treasured book.

A grim tale of rags to riches, one without a happy ending but one that captivated him nonetheless.

He did not understand it at first, he spent more time learning the words in the book than he did reading it but as he aged, but he understood enough that the man in the book was like him and that single book sparked a fire within him that raged for the rest of his life, until now, until that fire was doused by the freezing winds of death and weakness.

It was at that age, tender age of five, that he knew that he would do everything he could to be like that man, to escape the misery he'd been born into like that man.

Only later when he left Primary school did he understand the true message of the book.

Power was necessary to have the reigns of your own future, to shape your destiny through your own hands, to break free from the constraints that held you.

His parents taught him many things, not on purpose of course. 

His father taught many things about human nature...the ugliness that could be hidden beneath a mask of civility and falsehood.

His father was a man of community, well liked and respected. A man who abused his son and wife behind closed doors and none were the wiser. That had been his first lesson of many.

His mother taught him that reliance on others was something that only the weak did. 

Her meekness and lack of care for his wellbeing when he'd be disciplined, turning away from him when he'd begged for her, confirmed that there was none but yourself that you could rely on.

He started primary school, cynical and driven as he set himself on his path to do well at school. 

Early on, it became clear to all that he was intelligent and in the end, he skipped years and finished primary at age nine.

His years under the careful care of his father helped him immensely when it came to perception and how to make one appear as something else. Perception mattered and he took that lesson to heart. 

In the end, he succeeded and managed to obtain a scholarship at an elite boarding school once he aced the entry examination.

His time at the boarding hadn't been easy, not at first. He'd been from a poor ethnic background, riding on a scholarship years younger than his classmates. 

A Perfect victim. Or so they thought. 

It hadn't taken long...only a term and a half until they understood that he wasn't one to aggravate and by the end of his time at the boarding school, he managed to charm them all and obtained links with wealthy families that would have proven useful, had he not a terminal condition. 

He sighed and got off the edge and made his way towards his bed. He opened the drawer by his bed and grabbed his degree certificate.

He went to Cambridge at age fourteen to study Mechanical Engineering finishing with a Masters in Computer Programming.

He succeeded, in the end, only with his engineering degree, graduating with a 94% grade.

It didn't fill him with satisfaction, only bitterness that he was going to be dead before he achieved any of his goals, despite how hard he worked to get there as fast as he could. 

Everything he's done...the subtle manipulations of his peers in school to cheat them of their money to fuel his efforts to become independent from his parents, the blackmailing he'd done to one of his classmates parents so he'd get accepted to Cambridge with a scholarship.

All of it was for nothing. 

His hands trembled he gripped the certificate before he took a deep breath and set it aside before he returned to lie down on his bed, forcing down the resentment he felt. 

The next few months were terrible as he felt himself slipping until, the day came that he knew that his death was approaching. In his few moments of coherence, he could only think of the unfairness of his life before he closed his wet eyes and accepted that he was going to die today.

He let himself go, slipping into unconsciousness, knowing that he'd never wake up again.

-Break-

23rd of September 1924

He came aware with a jolt; he gasped desperately sucking in as much air as he could. He felt strange; he had never felt anything like what he was now. He was bombarded by illegible noises and smells, and he involuntarily cried out in pain with the sensory overload. But the sound that had come out from his mouth was neither his voice nor was it an adults'.

He opened his eyes to find out what was going on but quickly shut them as the brightness of the room near blinded me. He focused on what he could feel and he could feel that he was being held aloft by something and that he was covered in some kind of liquid that was quickly becoming cold.

Before he could dwell on it, he felt something wash over him and the sticky substance was gone and now felt the full brunt of the cold. he felt himselfbeing lifted and carried by what seemed like massive hands and had been set on a smooth and soft surface and then he had been wrapped up by what he assumed was a blanket. 

He carefully opened his eyes and began to quickly adjust his eyes, blinking away, until his eyes had adjusted to the influx of light that entered his eyes. He began to see silhouettes of figures and began to feel overwhelmed by the disturbing presences. He tried to move his body but it felt unresponsive, the most similar thing he could describe it as was paresthesia.

The one who approached him seemed to be a feminine figure and he focused on her face. She lifted her hand and it had held some kind of thin stick or rod and it glowed in a purplish colour as it was pointed at me. He could feel something wash over him and he felt himself calmed and soothed to the point that he no longer felt agitated or afraid.

He focused all his attention on the woman. Her lips were moving and he focused on what she was saying.

"-e's healthy and he has been calmed. He was in a panicked state until I put him under calming and warming charms" the woman said.

'calming and warming charms?' he thought confusedly.

He was lifted and carried somewhere and he refocused his attention to his current situation. The woman who had done something to him to calm him was carrying him as she walked to somewhere until she stopped and shifted him and bent over and handed him over to another pair of hands that held him delicately.

He was brought closer and he looked up and saw a woman staring down at him with a soft expression on her face and loving expression on her face.

'She's beautiful' he thought to himself as he took in her appearance. She looked tired and haggard but beyond that, he could see that she was a beautiful woman.

Her face was heart shaped that was accentuated with her curly brown hair and the greenest eyes he had ever seen. Her nose was pointed and her cheeks were reddened which he assumed from the exertion that she was under.

Just as he was lost in her face, she too took him in.

Anne POV

"Hello there, my son. I'm happy to finally meet you." She said softly with an accent that he couldn't quite place.

She looked at him with a loving expression with an underlying hint of relief that lay below the surface.

She wasn't completely calm after her nightmare had played out right in front of her. 

Her baby boy hadn't been breathing and it had taken what she felt like was hours, though a few minutes in reality, for him to breathe on his own. 

This would be her last pregnancy as her body would be unable to carry another child.

This had been her sixth pregnancy and only her second successful one. 

Her daughter's birth had wrecked her body and it had taken years for her to successfully heal. Thankfully this pregnancy had been much easier and at the same time more difficult as it truly had been her last chance to give birth a male heir.

She took in his appearance and she could see black tufts of hair on his head. She looked at him and saw that his eyes were firmly on her as her eyes were firmly on him. She dangled her fingers in front of him and he was tracking it. 'A perceptive child aren't you?' she thought to herself amusedly.

*Knock* She looked up and saw the door opening and saw that it had been her husband that was entering. She smiled at him tiredly and he returned it to her. He looked as he had always done; well kept and handsome.

He had handsome aristocratic features, with high cheekbones and an angular shaped face that were accompanied with grey blue eyes and shoulder height midnight black hair.

"Markus" she said softly before returning her attention to the bundle in her arms.

"Anne" he said gently as he saw down in the chair by the bed, his eyes showing concern yet relief. 

"How are you and our little boy feeling" he asked quietly. She smiled at him and handed her baby over to him.

"We're both fine. There was a scare when he wasn't breathing but he pulled through." She smiled deeply as she glanced at her miracle though her tone shifted into one of tiredness, one filled with solemnity "I felt so helpless when they took him away but it worked out in the end" she sighed tiredly.

She closed her eyes and leaned back into the bed. 

After a few minutes, she opened her eyes and looked at her husband and child.

He was appraising her boy with a gentle look and a small smile that could only be seen if you knew him. Her husband wasn't one that shows much emotion but he was caring man to those close to him and she loved that about him.

"Hello my son. You gave us quite the scare when you didn't breathe when you came into the world. But like anyone of my blood, you were strong and pulled through" he said with a broader smile that she seldom saw.

He looked at her "He has my hair and it looks like he will most likely have my father's eyes when they darken. He'll be a handsome man once he's grown" he stated with a chuckle.

She joined him with a small laugh "Of course, is my son after all" she said as prim as she could manage causing him to chuckle.

"I haven't named him yet. I was waiting for you to come and name him" she stated.

Markus hummed and looked at their baby contemplatively. "I had intended to name him Henry but looking at him now, I think Atticus suits far better. What do you think?" he asked

"Atticus" she tried out, sounding it out and thought that it was a strong name. She looked at him and gave him a small nod "I agree" she said.

Atticus POV

"Hello my son. You shall be named Atticus Markus Sayre." his 'father' stated. 

That had been the last straw in what had been an unreal and tiring day that seemed to hit him again and again with revelations that he didn't know could be possible and promptly drifted off to sleep.

For the next few days, he had only intermittently been conscious and mostly during those times, had spent it being fed, changed by some of the staff or being held by his new mother and father.

When he had recovered to remain conscious long enough, he took the opportunity to review what he knew so far. He last remembered falling asleep until he found himself in this situation.

He had been familiar with the concept of reincarnation though he had never truly considered it to be possible never mind the possibility of being reborn in the world he was in and in the manner he had been brought to it.

In the last few days, things became a lot clearer and he had used the time to spend whatever time he was awake grasping as much information as he could and it only solidified what he had at first suspected when the information yielded confirmations.

He had been reincarnated in the wizarding world…yes that wizarding world. 

He knew that he wasn't hallucinating because the possibility of such vividness of his surroundings and the manner the people around him acted certainly made it all impossible that it wasn't real. At least that is what he told himself. Perhaps he was insane and didn't know it. 

In any case, he came to accept his new circumstances, insanity notwithstanding, and all that came with it.

There were many questions he had and he suspected that there many of those questions would never be answered with finality and surety. 

Those questions however would not take precedent as he had far more important things to consider and act upon in his new life.

His new parents were named Markus and Anne Sayre. From what he could understand, he had stopped breathing momentarily when he had been born and needed emergency intervention.

From the timescale, he suspect that was the moment he was awakened when he breathed his first breathe in his new body. he hadn't been able to see much magic performed, other than diagnostic scans being performed on him or warming charms but he could feel more than what he remember being able to feel in his last life.

He felt it when he was being held by his mother or his father. It felt instinctive and both of them felt different from each other but it had the same effect.

They both exuded an air of protectiveness over him which was an alien experience for him. He had been alone all his life and he had to scrape and fight to have what he had and it had left him cold, ruthless and melancholic.

He felt strangely comfortable with the both of them which might well be partly responsible by his infant biology. He certainly had never felt so lethargic in his life.

Rounding away from that train of thought, from his observations from the interactions that his parents had with the staff of St. Mungos, it was obvious that they were nobility and had garnered high levels of respect and deference from the staff.

It boded well for him, in truth, as being born in an influential family would allow him to wield that influence in the way he want though that was only secondary to the most important thing, now, in his life.

Magic.

He was born, at least he hoped so – it would have been truly cruel to being born without magic – with magic and he could only feel a malicious delightful glee at the opportunity that was available to him now.

He'd read the Rowling books when he was a child. It was one of the most accessible series of books in his childhood and he had been gifted it by one of his classmates' parents for his 7th birthday.

He didn't like how much the disdain that the Potter boy received from his relatives resonated with him but he had pushed past that along with the contempt he generally felt for the boy for his naivety and he had wondered at the marvellous world the series were set in.

It was fascinating and it had so much potential, depth and more importantly, for a child such as him at the time – one who had, very little of anything in any capacity in his childhood, there was POWER in the fingertips of people that drew him in.

There were so many paths to power and to grow magically that it sparked his imagination. There were many ways that should lead to immortality or at the very least an exceedingly extended lifespan and it should all be within range for those who knew how to seek it or achieve it.

Being born in 1924 was not a terrible starting point in truth. In fact, it may well be very advantageous as it meant that he was born before Riddle, before the war got bad with Grindelwald, before Dumbledore's rise.

It would give him the space he needed to grow and the paths of power and success were open to him, waiting for him to tread it and…

Where others had faltered, he would not. He grinned wickedly to himself.

-Break-

Life as an infant was an experience that he hoped he'd never have to do again, not that he believed that it was likely. 

It was exhausting pretending as much as he did and only the fear of being discovered had him keep it up as much as he could. 

He knew he was far from successful.

It wasn't terrible being cared for as much as he was but he loathed losing his independence. Atticus had to get over his feelings of indignity very fast when he was being fed from his mother's body.

His emotions that Atticus had spent years in carefully repressing had been thrown out of balance. 

Atticus felt like a child, despite having an adult mind. 

Even so, very early on, he gained the reputation of a quiet but obedient child that hardly made a fuss excepting of course whenever he needed something at which point he brought attention to himself by crying out.

He knew that wizarding families were obviously far more used to odd things, things that stood out or did not make sense and so he had endeavoured to ensure that his behaviour did not attract unwanted attention upon himself.

He acted like a child which in truth with the manner his hormones and emotions were was not as difficult as it were.

Physically he was unable to say any coherent words, which likely would not feasible for a year or two and embarrassingly he had little control over his body.

The person who spent most of the time with was his mother. She was his constant companion and seldom let his caring go to the caretaker, a certain Ms Florence.

Ms Florence was a young lady, possibly in her late twenties or thirties and she had a kind disposition. She was not a beauty but she was attractive enough. She had a heart shaped face that had a soft feminine quality.

She had light brown hair and light blue eyes. Her role seemed to be predominantly a governess esque kind of role within the household. The other non family member within the home was Gerold Dayton who seemed to be someone who worked predominantly with the patriarchs of the family.

His mother's affections and gentleness had truly messed with him at the beginning. The intensity of his emotions, the hormonal body, it all contributed to difficulties reconciling in the way he was treated in comparison the way his previous mother had been and it had taken time for him to come to terms with.

She knew and noticed his discomfort and she had been extremely patient and kind in the way she dealt with him. Luckily, the fact that he was a baby masked much of the oddness that he was displaying and had been explained away.

Eventually, his discomfort gradually reduced as he spent time with her and the effort she put in. She oozed protectiveness and warmth in a way that made him think that magic had to be involved, was responsible for setting him so at ease once he allowed himself.

Her presence, being held in her arms, felt like a warm blanket. She would hum to him, often sing melodies in a language he did not quite recognise and it often soothed him to sleep.

Her affections and her care had taken time for him to get used to it but he did not hate it...he had felt a possessiveness over her and he was, for in the first time of his life, feeling warmth for another person.

In his infancy, his mother enjoyed taking him out for a stroll and he was thankful for it and made sure to give indications, expressions that he enjoyed it. From those strolls, he managed to get decent understanding from the home that he could call his now.

The Manor was grand, in every interpretation of the word.

The three story tall manor had a way of belonging to the earth it graced. It was seated upon an elevation that looked over a large mountainous forest to the west and south and a small lake to the east which gave an almost panoramic view of the grounds at the right location.

The Manor was secluded, nestled in between the surrounding nature, no other sign of civilisation for as far as the eye could see.

As his mother took him on theses strolls, Atticus could feel the presence the manor exuded as they walked at the edges of the grounds. Atticus could not truly understand it but it felt as if it embraced him, welcoming him to home.

The pathway from the entrance of the manor to the gate was flanked by a beautiful landscape; a variety of plants and trees that were masterfully arranged, which flanked the steep granite pathway that lead from the gates to the entrance of the manor which created a mirage of controlled wildness of the artificially arranged nature surrounding the manor.

Once inside, the scale and opulence of the manor becomes obvious. Decorated tastefully, the entrance hall was themed in whites, silver and dark green colours with wide curved stairs on the left hand side coming into view. The interior of the manor seemed as it if was carved from marble, for every section had marble stone with deep grey veins running through them.

The right hand side of the entrance hall led to a room through downward leading stairs which lead to the floo. The fireplace itself was located at the lowest point in the room which he believe was the intent as it would give any intruders a disadvantaged position to strike from.

Both this room and the entrance hall had suits of armour adorned on two sides of the room and they numbered by over two dozen. He had no doubts that it was part of the defensive wards of the manor.

The rear of the entrance hall leads to a massive room where the hearth of the home was located and where most of the guests and family would be entertained. In that room, the walls were decorated with portraits of ancestors and paintings of scenes, regions and battles.

Apart from being carried around by his mother, he got to know the rest of his family more. He had a Scottish grandmother, Marie, who was kind and seemed to be have a mischievous streak in her. He had a grandfather and great grandfather who seemed stern but caring in their own ways.

He had an older sister by six years who was an energetic and pleasant girl who enjoyed spending time with him.

She shared their mother's eyes, the same shade of bright emerald green but she had their father's midnight wavy black hair. She tended to always have a book on her when she was with him and after coaxing her in an obvious manner, she began to read out to me.

She had a type of books that she always liked to read that were mostly wizarding stories that seemed to be about notable people in wizarding history. He enjoyed those sessions as it gave much relief of the monotony of his current situation until he was a little older.

Those early months of his second life represented a paradigm shift in his personality. As he continued to grow, he began to notice subtle but certain personality and behavioural shifts within himself.

In his old life, before his diagnosis, he had been cold as a result of his life and had grown calculating and remorseless in his pursuit of his goals and he carried a great deal of anger.

It wasn't an explosive anger; it was a cold anger that was always persistent within him. So far, the cold anger he'd always had was no longer within him.

He thought a great deal about this and he knew that it had begun to manifest within him at an early age when he had understood that there were people who would actively work against you and make your life difficult.

It had begun with his parents, continued by certain neighbours and perpetuated by so called peers during his academic years.

His cold anger had fuelled him, spite had drug him forward and vindictiveness had him enjoying setting people in their places and he had aimed to leave his mark on the world through his intellect and capabilities. 

It had been largely left simmering by the time of his death when he knew that he wouldn't achieve any of his long term goals but, until now, it hadn't gone into remission.

The main reason for the disappearance of his anger was because of the sheer number of opportunities that he now had in his new life and the choices he now faced in this life.

He had a great deal of options available to him than he ever did in his previous life and not only that; he had genuine power in his fingertips once he learned to wield it, to change reality to his whims.

He could feel hints of the power coursing in his veins at times, waiting to be unleashed with eagerness. He was born within a pureblood family that was nobility and this would effectively open any doors for him.

He would, with utter certainty, dedicate himself with the study of magic and become as close as he could to be the quintessence of magic, the greatest of the greatest of magicals in existence, in future or past, there would no denying him.

However he knew that there would be many challenges that he would need to overcome. In those early months where he had been unable to do much of anything, he was thinking on the events to come.

This time period was defined by a war that engulfed much of the civilised world. Europe was set ablaze with war, both in the muggle and the magical world.

He did not know what Grindelwald's ideology and movement was beyond knowing that it was for the dissolution of the Statue of Secrecy and for domination and oppression of the muggle world under the leadership of wizardkind, no longer hiding themselves and magic from the entirety of the world.

He held sympathetic views in some capacity to it. As a magical now himself – he was certain he could not be a squib – the status quo was not sustainable. 

But from what he knew of Grindelwald's character, Grindelwald's path was the path of a tyrant and mass murder.

He did not care. He did not care for the average magical and he definitely cared not for muggles. He had not cared for people in his first life. But he did care for the magical world, the awe-inspiring creatures, the magical flora, and the general idea of a magical society and not the one he was born into.

He also began to care for his family and therefore he cared about the inanity that the wizarding world had tied itself with for it affected him and his family. 

And so, he would have to choose a path.

The most difficult path would be fraught with danger and had a high chance of death. It is also the path of highest reward. It would be the path that gained him international acclaim if he became successful.

The major disadvantage of becoming internationally acclaimed was that it was a double edged sword, especially in a world where power was tangible.

He did not want rule the wizarding world in any capacity.

Everything he knew of it indicated a potentially dysfunctional society that would require far more effort than he was willing to put in and it would set targets on his back and his family's.

He was willing to provide the tools and knowledge for the wizarding world to aid itself but force was out of the question for him.

Acclaim would give him the platform he would need to meet people, important people who could very well useful in his plans.

He knew, to change the magical world, particularly magical Britain, it would require monumental effort that ultimately was likely to fail. If he were to attempt to do so, he would likely be classified as a Dark Lord in his attempts to change centuries of prejudice.

But…he could create a sanctuary of a sort as he felt no loyalty to the Isles. 

A refuge of people who would meet his criteria and help him build a society that could endure of the inevitable dissolution of the statue of secrecy, whether it was in fifty or in a hundred years.

Participating in this war on the side against Grindelwald would undeniably aid in his quest.

He suspected that war between muggles and magicals would happen eventually. 

He just didn't know how devastating it could be.

The upper echelons in some muggle governments must know about magicals and to think that they would not plan ahead would be considered folly.

Once it became public knowledge that magic exists and there are witches, wizards and all kinds of magical creatures among them, mass panic will occur. 

The human response dictates it so.

Excessive fear would lead to irrational, irresponsible responses and politicians and religious figures would only fan the flames. Exaggerated beliefs about the threat they posed would become common once the novelty of magic was worn off, the unnaturalness they represented, rooted in religious dogma and texts, and would become the rallying cry of those who would seek to capitalise on fear.

He had seen it before and history is littered with people who were marginalised or exterminated for one reason or another.

However, this time, if the magical world does not navigate exposure in the best possible way, which even then may not be enough, the actions of the muggles would be far beyond anything they had ever done before.

Mutual Assured Destruction and rare sensible individuals had been the only things that had ensured the world hadn't been engulfed in nuclear winter and setting off the next great dying off, quite likely to have been the very last one.

It could not be guaranteed that rogue elements of governments wouldn't set off nuclear weapons in regions that they identified to house significant numbers of magicals.

Witch hunts would become exponential and experimentation on children would become accepted, just as experimentation on Blacks, Jews, Chinese and so on had been accepted during various stages of recent history.

In order to be capable of shifting the magical world on the scale he wished to, he would have to be someone of influence, of enough stature and clout, he would need to be extraordinary. 

And for that, he would have to take active participation in war as it was the easiest and most direct route of entering the public consciousness.

The problem however was Grindelwald himself.

He held no illusions that he was facing an insurmountable challenge to match Grindelwald at an age of nineteen or twenty. 

If he remembered correctly, Dumbledore and Grindelwald were born in the late 19th century, meaning that by 1945 they'd be in their sixties or so.

For him to be able to match Grindelwald, to exceed him, would require him to achieve almost insurmountable level of magical capability. 

Grindelwald also wielded the Elder Wand. It was an uphill battle.

The easiest path, and simultaneously the path of obscurity, was to ignore the war and stay far away from it. The war as far as he knew had been going on for decades until it was ended in 1945, meaning many members of Grindelwald would be hardcore veterans.

The combined forces of ICW and liberators would eventually defeat Grindelwald's movement and Dumbledore would eventually defeat Grindelwald.

It would mean his path of having enough influence would become more difficult as Dumbledore would fill the shoes in the public mind that he wanted to occupy.

The impressions that he had gotten of Dumbledore from the books, despite being child friendly, seemed to suggest that he would not become an ally for the beliefs he held, despite him not wanting a war with the muggles in the first place, and having Dumbledore as a political enemy, the man who defeated Grindelwald would be something that he did not need.

If he stayed out of the war, then it would mean that the chances are that events would play out, mostly, in the same manner as they did in canon and Dumbledore would eventually get off his perch and defeats Grindelwald.

That thought soured greatly. 

From everything he had read in his previous life, Dumbledore defeating Grindelwald had cemented his legacy and was held in reverence by the wizarding world, at least in the British Isles.

Dumbledore was someone ill suited for the amount of influence he wielded, influence he had wielded so very poorly.

He fitted himself be the voice of supposed reason and of highest morality however he had never wielded his influence in the way he ought to have.

Dumbledore had deep character flaws in the books, flaws that Atticus suspected had damaged much of Magical Britain but he knew that Dumbledore likely held off worse consequences for many disenfranchised.

The magical world, after Grindelwald's defeat was primed for another great war as the issues within the magical world had never been resolved to a successful degree and by the end of the story in Rowling's books, probably weren't resolved either.

From that defeat of Grindelwald, Dumbledore within decades managed to gain insurmountable amount of influence within the Wizarding World in the form of Headmaster of Hogwarts, Chief Warlock and Supreme Mugwump.

Dumbledore was said to hold beliefs that muggles were equal to wizards and he in some respects agreed to the notion in an ideal world whereby prejudices and so on did not exist and where wizards and muggles were simply humans who may or may not have some additional abilities.

The problem was that the human psyche did not work like that and for all the advancement, tribal elements still had heavy roots in society. 

He had fully intended to exploit those elements but with magic at its core. That hope, that belief in the goodness in people falls short as he should know.

Humans have biases, they have preconceptions and more importantly they are of the belief they are top of the food chain. 

Once it becomes discovered that there is a society, or a collection of societies, that are capable of bending reality to their whim, of bending the minds of people to what they wish, there would be massive societal unrest on a unprecedented scale.

He knew that he would have to campaign hard to let everyone see the true danger of muggles and how dangerous ignorance was for the survival of the magical world. 

He'd gotten a second chance of life. He'd be damned if he let the stupidity of both groups destroy everything.

He had considered washing his hands off the matter and simply focus on becoming the greatest wizard of all time...but he had grown...possessive of the family he was born into. 

There was no reason to do both.

He would need allies, he would need a support base. Luckily for him, he had everything he needed to do just that. 

And if he didn't…well…

There wouldn't be anything in the world that could stop him getting what he wants.