Battle with the Servants

OmegaMon, carrying Ritsuka, Mash, and Olga Marie, flew at a low altitude, exploring the city of Fuyuki. While they searched the city, they occasionally defeated groups of skeleton soldiers. However, a small problem arose.

The problem was that OmegaMon had no knowledge of the current anomaly. Olga Marie realized this and began to explain. She thought it was not good for their ally, the Holy Knight, to be completely unaware. Why were Ritsuka and the other candidates gathered in Chaldea? OmegaMon quietly began to listen, even as Ritsuka fell asleep during the explanation.

In 2015, the "Chaldea Security Organization" guaranteed the safety of humanity for 100 years into the future. However, according to the observations of the future observation lens called "Sheba," it was proven that humanity would perish in 2017. Without any warning, without knowing the cause.

As a result of investigations by Chaldea researchers, an "unobservable region" was observed in Fuyuki City in Japan in the year 2004, according to Sheba's observations. Chaldea judged this as the cause of human extinction and proposed the Rayshift experiment to the United Nations, which was approved.

Rayshift is the act of spiritualizing humans and sending them into the past to intervene in events. It is a form of time travel to the past, but not everyone can do it. It requires exceptional magical circuits and human beings with Master aptitude. Ideally, they should have become Masters of Servants.

"Thank you for the explanation. I have grasped the situation to some extent. I knew before meeting you that this is a world of the past, and this place is Fuyuki City. But... is it permissible to change the past? I think it would have some impact on the present..."

"I understand your concern, but that's not a problem. This place is a hole that suddenly appeared, completely separate from the original timeline recorded in the observations. You don't need to worry about fitting the pieces together."

"I see. So, it's safer and more reliable than regular time travel, and even if we make changes to history, it can be compensated by time alteration, is that right?"

"You catch on quickly. To put it simply, this Singularity is like a stain that has seeped into the fabric of human history. Our mission is to clean up that stain."

Although they had only been involved for a short time, Olga Marie had started to build a relationship of trust with OmegaMon. Firstly, OmegaMon was a divine spirit and had helped her. Secondly, the tone of the Holy Knight's voice was that of a young man, combining a sense of ease with a dignified manner. With a dignified bearing and a gentle and calm demeanor, as well as a polite personality, Olga Marie was also gaining trust from the Director.

"By the way, what exactly are Servants in this world? Ritsuka and I have a partner Digimon and Tamer relationship, so is it similar to that?"

"You don't know about that either... Well, it's alright. I'll explain. Well, you can say it's similar to the relationship you mentioned..."

Olga Marie began to explain about Servants to OmegaMon. Servants are the highest-level familiars in the world of magic. They are the embodiment of various heroes, achievements, and concepts recorded in human history, summoned as spiritual bodies.

Whether they were actual heroes or fictional heroes, it doesn't change the fact that they are "information born on Earth." Converting the accumulated information on Earth into a form that benefits humanity, that is the summoning of Heroic Spirits.

It is natural for modern humans to use the legacy of the past, and preserving the future using that is also an instinct of living beings. Ritsuka, in addition to being an existence greater than humans, has a contract with a familiar who serves humans. That's why they are called Servants.

"I see... So, Servants are familiar spirits created from past heroes, and Masters contract with them to employ their services, right?"

"That's right. And Servants have different classes, which vary depending on the legends and abilities of the heroes. It is difficult to completely reproduce the hero themselves as a spiritual body, as there are limitations to memory capacity. So it is necessary to solidify a certain aspect possessed by that hero. That's where the classes come in. They are roughly classified into seven types."

There are seven classes of Servants: Saber, Lancer, Archer, Rider, Caster, Berserker, and Assassin. Regardless of the Heroic Spirit, they are always summoned into one of these classes.

There are also Extra Classes like Mash, who is a Shielder. Exceptions exist for everything.

"The existence of classes serves another purpose as well. It is to conceal the true identity of the Servant... their name as a hero, or rather, their true name."

"I see. Heroes, despite their strength, are famous, so their weaknesses are widely known. It's like Siegfried's back or Achilles' heel, for example."

"You catch on quickly. That's why Servants conceal their true names with their class names. As long as their true names are not known, the chances of their true identities or weaknesses being exposed are slim. There's another reason as well. The Servant's trump card, their true essence, the manifestation of the miracle and existence of the Heroic Spirit. That is called a Noble Phantasm. If their Noble Phantasm is known, their true name will also be revealed. It's to prevent that from happening."

It's quite complicated, or rather, difficult to grasp. But I have to understand and absorb it, or else it will be difficult ahead. I have no knowledge about this world.

After receiving a brief explanation about Servants from Olga Marie, OmegaMon then received an explanation about Chaldea. The "Chaldea Security Organization," officially known as the "Chaldea Security Organization Finis Chaldea."

It was a research institute where researchers gathered, regardless of the distinction between magic and science, to observe and prevent the definitive extinction of humanity by observing the world that could not be seen with magic alone or measured with science alone.

Although the funding for Chaldea's establishment came from a joint effort by various countries, the majority of it was provided by the Animusphere family of the Clock Tower in London. While it was nominally a research facility, its internal regulations were on par with a military due to its importance.

(Director Olga Marie seems to have a lot on her plate... I hope I can at least become an advisor or find a place to belong.)

Later, they received communication from Romani and learned about Olga Marie's situation. OmegaMon began to think about supporting her considering her position.

Originally, she was also one of the Master candidates, but three years ago, her father passed away, and despite being a student, she had to take over Chaldea. From then on, every day became challenging, especially since she became the head of the Animusphere family.

She was already doing her best to maintain Chaldea when an anomaly was discovered in the small pseudo-singularity, the pseudo-environment model known as Chaldeas.

The future that was supposed to be guaranteed for a hundred years ahead became invisible, and criticism poured in from the Association and sponsors. They had to resolve the situation as soon as possible. Olga Marie was driven by the concept of this imminent threat.

"By the way, the Fuyuki City mentioned in the documents is so different from this Fuyuki City..."

"What on earth happened in this city?"

"Did history slightly go awry... or did something happen? No, is happening. I don't even know that far. But there's one thing I know. And that is..."

Afterward, Olga Marie explained about Chaldea again. They observed the future using a model of the Earth called Chaldeas and aggregated records of the past using a familiar named Laplace.

Laplace observed hidden information that never became public history, things buried in darkness. Through these observations, they confirmed the occurrence of a unique Holy Grail War in this city in 2004.

"Which means... this city became like this due to a battle between Servants, an anomaly in the Holy Grail itself, or the intervention of someone else. Those are the possible explanations."

"Your instincts are really sharp, OmegaMon."

"Do you think so? I still consider myself slow..."

The system of the Holy Grail War in Fuyuki is simple. Seven Masters compete against each other, and the final victor claims the Holy Grail in a survival battle.

Chaldea learned about this fact in 2010. Olga Marie's father, the former director of Chaldea, Marisbury Animusphere, used that data to create the summoning ritual. That was Chaldea's third invention, the Guardian Heroic Spirit Summoning System, Fate.

"According to the records, here, the battle ended with the victory of Saber. The city was not destroyed, and the Holy Grail War ended without anyone knowing about it... But, as OmegaMon said, it seems that this situation arose due to the battle between Servants, an anomaly in the Holy Grail, or the intervention of a third party. It appears that the outcome changed due to it becoming a Singularity..."

"This anomaly is affecting human history, and we can no longer see the future a hundred years ahead. Our mission is to restore this anomaly. There must be a cause somewhere that disrupted history... That's the situation, right?"

"That's correct. If we analyze and eliminate it, the mission will be completed. We can return to Chaldea... By the way, Mash, you can't use your Noble Phantasm, right?"

"Yes. I don't know who the Heroic Spirit I fused with is, and I can't fully utilize the power of their trump card, the Noble Phantasm."

Servants possess unique skills and weapons called Noble Phantasms. They are trump cards inspired by the legends and achievements of the heroes. For example, Excalibur for King Arthur or Balmung, which Siegfried obtained through bathing in dragon's blood, granting him invincible physical abilities.

In Mash's case, she possesses a Noble Phantasm, but its output is reduced, and she can't fully unleash its true value through the release of its true name. Besides, she doesn't even know what her weapon, the large cross-shaped shield, really is.

"I have to do something about Mash's Noble Phantasm as her Master..."

"Uh! I'm sorry, but I want you to get off me immediately. I sense someone's 'Wave Code.' Moreover, it's a stronger reaction than the skeleton soldiers we encountered earlier!"

While flying at low altitude, OmegaMon detected the 'Wave Code' of someone ahead and tightened their expression.

This was a different reaction from the skeleton soldiers they had been fighting since arriving in this world. It harbored a much stronger power. It might be a clue to the cause of the anomaly.

"No way... a Servant!?"

"Mash, it's another Servant! We can handle this, right!?"

"Yes. I'll do my best!"

Before them stood a Servant. She was an enchanting beauty with her field of vision sealed by a visor, but her silhouette was black. They didn't know what Heroic Spirit she was.

Mash, also a Servant, prepared her shield to fight, but OmegaMon noticed that she was scared to fight and stepped forward. Making metallic sounds, OmegaMon stood beside Mash.

"I will fight too. A 2-on-1 battle goes against the code of chivalry, but unfortunately, I don't mind such things."

"OmegaMon-san...!"

"I'm counting on you, OmegaMon! Mash!"

OmegaMon had shrunk its size to about two meters. He volunteered to fight alongside Mash. Although it was his first time fighting as a Servant, he was determined to fight because there was no other choice. It was for the sake of Ritsuka and Mash, who once had the same power, and for the sake of protecting this world. OmegaMon was about to confront the enemy Servant in battle.

ーーーーーーーーーー

"Prepare yourselves...!"

"Let's go, Mash-san!"

"Yes, OmegaMon-san!"

The Servant exuded an evil aura. She held a short sword with chains in her right hand and grasped the chains with her left hand. OmegaMon assumed a stance, and Mash held up her cross-shaped shield, which was as tall as she was. As they cautiously kept their distance from the enemy Servant, she made the first move.

The short sword with chains was directed towards Mash. Reacting to the swiftly approaching blade, Mash blocked it with her shield and counterattacked with her sword, initiating a shield bash.

"Hyah!"

"Kuh!!"

The enemy Servant was pushed into a defensive position by Mash's relentless attacks. Meanwhile, OmegaMon unfolded a black-shining cannon from the gauntlet on its right hand, shaped like MetalGarurumon's head, and aimed it at the enemy Servant.

Compressing the absolute zero coldness stored within its body into the form of a bullet within the cannon's interior, OmegaMon fired a condensed blast of freezing coldness, shimmering with a bluish glow, at the enemy Servant.

"Mash-san, get back for now!"

"Yes, understood!"

At the same moment Mash heard OmegaMon's words and leaped back, the blast of absolute zero coldness was unleashed.

The enemy Servant instinctively evaded the barrage, but the area grazed by the blast quickly froze. The point of impact turned into an icy world in an instant.

"No way...!"

"Now, Mash!"

"Yes!"

"I'm furious...!"

The enemy Servant, surprised as her body began to freeze, was not able to take advantage of the opportunity. Mash, still unable to move under immense pressure, tried to follow up with an attack, but just before she could, the enemy Servant took a certain action.

She removed the visor that covered her eyes, which had been sealing her field of vision, and revealed her eyes to Mash for the first time. Eerie red light emanated from her eyes, and Mash instinctively thrust her shield in front of her. She thought an attack was coming, but it was different in reality.

"Huuh... So this is...!"

"Mash!?"

"I can't believe you could withstand my Mystic Eyes. I thought you would turn to stone..."

"Mystic Eyes... petrification? I understand, Mash! That Servant's true name is... Medusa!"

"Medusa!?"

Mash kneeled on the ground, overwhelmed by an immense pressure. While OmegaMon and Ritsuka were astonished, the enemy Servant distorted her expression.

Originally, she had intended to petrify Mash, but due to Mash's high magical parameter of B, it didn't go as smoothly as planned. Furthermore, Olga Marie correctly guessed her true name. The enemy Servant was Medusa, the youngest sister of the Gorgon Sisters from Greek mythology, portrayed as a snake-like monster that turns people into stone.

"I may not be in the mood, but I'll turn all of you into stone."

"Not gonna happen!"

Medusa tried to petrify Ritsuka and Olga Marie, but OmegaMon stepped forward, blocking her path.

Ritsuka and Olga Marie managed to avoid being petrified, but OmegaMon was still affected to some extent by the Mystic Eyes. However, for some reason, his body didn't turn to stone, and he didn't exhibit any signs of being under immense pressure.

"My Mystic Eyes don't work...!? You're not a Servant. Who are you?"

"Just a holy knight!"

As an Heroic Spirit, OmegaMon didn't possess magical energy. However, he nullified the effect through the protection of his pure white armor, the divine-grade soul, and the strength he had built up through battles during his lifetime.

The holy knight standing before her was immune to the petrifying effect of her Mystic Eyes. Realizing this, Medusa, with a formidable expression, changed her target to Mash, who was still unable to move. She attempted to throw the chained short sword at her, but she couldn't.

"My, defeat... I see..."

"It's not my victory but your mistake in attempting to attack her first."

To attack Mash meant receiving an attack from OmegaMon. As the holy knight aimed his Garuru Cannon and concentrated the absolute zero coldness within it, compressing it into the form of a bullet, he fired a freezing cold blast, shimmering with a bluish glow, at Medusa.

The attack was unleashed at the moment she was about to launch her own attack. Medusa attempted to evade it, but the speed of the absolute zero blast surpassed her, and the bluish blast of freezing coldness struck her directly.

Realizing her own defeat, Medusa instantaneously froze. In an instant gust of wind, she disintegrated into particles and disappeared.

ーーーーーーーーーー

"Haa... We managed to win somehow."

"Yeah. Good job... Although I'd like to say that, we don't have time to rest. I just confirmed the presence of two Servants approaching us. And they're...!"

Normally, in Fuyuki City, the Holy Grail War would be taking place. The seven Servants would be fighting to the death, and it wouldn't be strange for there to be Servants without Masters. The enemies of Servants are Servants themselves.

While they were investigating the reactions of those Servants, they encountered Mash and engaged in combat. However, the previous Medusa wasn't an Heroic Spirit but something closer to a wraith.

"I've found it! New prey!"

"That one is an Assassin-class Servant...! Then, the other one..."

"I sense a presence that doesn't belong to a Servant, but it's not from the head... Oh well."

"A Lancer-class Servant...!"

Before OmegaMon stood two Servants. One was an Assassin with a white skull mask, a black cloak, and a stick-like right hand covered in black fabric. The other was a stern-looking warrior monk Lancer.

While they had managed to defeat one Servant with the cooperation of OmegaMon and Mash earlier, now they had to face two Servants. Realizing this, OmegaMon raised his voice to encourage Olga Marie and Mash, who were being engulfed in the atmosphere.

"There was a certain soldier who said, 'It's third-rate to lick your lips in front of prey.' We're not the kind to lose to evil spirits like you!"

"That's right! I'll never give up!"

"Good, I like that. The courage not to give up even in adversity. And you, knight I've never seen before, you possess something amazing."

"Who are you?"

"What do you mean? Can't you tell just by looking? I am Caster, the Servant of the Caster class."

OmegaMon nodded in response to those words, and Ritsuka raised his voice. Just as the holy knight was about to face the two Servants, someone approached OmegaMon and the others.

He was a Caster-class Servant, a Celtic magician clad in a blue robe. Unlike the other Servants, he maintained his sanity and sought to assist OmegaMon and the others.

"Hey there, little miss. Don't worry about your skill. You're not losing to those guys. It's not a delusion. Is the bald guy your Master? I'll leave the instructions to him."

"Understood! OmegaMon, deal with Lancer. Mash and Caster, handle Assassin!"

Following Ritsuka's instructions, OmegaMon engaged with Lancer, while Mash teamed up with Caster to fight Assassin.

It was the first time for OmegaMon, who was accustomed to solo battles, to fight alongside Caster, who had a reputation of some sort. Their battle began.

ーーーーーーーーーー

"Mmmph!"

The battle between the holy knight and the warrior monk commenced. Lancer made the first move, charging forward with his naginata in hand, closing the distance and swinging his weapon with full force.

His target was OmegaMon's neck. It was a strike meant to be fatal, filled with the determination to finish it in one blow. However, OmegaMon bent his body and evaded the attack.

Then, firmly planting both feet on the ground, OmegaMon began rotating his upper body. His left hand transformed into a gauntlet resembling the head of WarGreymon, and he swung it upwards in one fluid motion.

"Haah!"

"It's over!"

The naginata was deflected by the upward swing. Lancer was left defenseless, and his torso was wide open. OmegaMon didn't miss this opportunity. With a downward swing of his sword, Gray Sword, he cleaved the warrior monk in half, ending the battle.

As OmegaMon observed Lancer disintegrating into particles and disappearing, confirming the end of the battle, he flipped the cape draped over his back and returned to his Master.

"Shaah!"

"Haa!"

"Ha!"

Meanwhile, the battle between Assassin and Mash & Caster had also begun. Assassin took the initiative, throwing his black-coated dagger, Dark, as a projectile from a no-motion position.

In response, Caster wielded his staff and launched long-range rune attacks, intercepting the magical projectiles. The clash between the magical projectiles and the runes caused explosions. Amidst the flames and black smoke, Mash closed in on Assassin and struck him with her shield.

Assassin was an assassin. While he couldn't boast high combat prowess in direct confrontations, he excelled in assassination and espionage. Even though Mash was inexperienced in combat, having the support of the seasoned Caster made a significant difference.

"Anzas!"

"This should finish you!"

"This... can't be...!"

As Assassin was hit directly by Caster's fireball and lost his balance, Mash followed up with her attack. His Spirit Core was destroyed, and he disintegrated into particles, disappearing.

The battle against the two Servants, Lancer and Assassin, ended. Thanks to Caster's assistance, OmegaMon and the others managed to overcome the crisis.

ーーーーーーーーーー

"Uh, um... Thank you very much. You saved me when I was in danger..."

"Yeah, good job. Don't worry about this much. It's nothing worth mentioning. But you should be concerned about your own body."

"Kyaa!"

After the battle against the two Servants, Lancer and Assassin, Mash bowed to Caster, who had supported her, and he responded with a smile.

"Don't worry about this much. It's nothing worth mentioning. It shows a broad-mindedness befitting an older brother. But then, suddenly touching Mash's body like that. It can't be described as anything other than sexual harassment."

While blushing deeply, Mash distanced herself from Caster, and OmegaMon, who felt a slight anger, approached Caster calmly.

"Oh, you've got quite a nice body! What a lucky break!"

"Hey, you're doing quite a lot to my comrade, aren't you?"

A clanging sound came from behind Caster, who had a smile on his face. When he turned around slowly, he noticed a black, shining cannon pointed at the back of his head.

Although it couldn't be seen from his white helmet, OmegaMon's sky-blue eyes revealed his anger. Observing the stern expression on the holy knight's face, Caster began to break into a cold sweat.

"U-Um, Mr. Holy Knight? Why are you pointing something dangerous at me?"

"Why? The reason is simple. It's because you sexually harassed my comrade. Isn't that something you should do to your wife or girlfriend?"

"W-Well, that's true, but..."

"I'd like to believe it was intended as a form of physical contact, but the other party might find it unpleasant, you know? Be more careful."

"Y-Yeah... I'm sorry."

After finishing his words, OmegaMon retracted the Garuru Cannon. Although he seemed angry with Caster, he subtly admonished him. In response, Caster lowered his head apologetically.

Witnessing this scene, Ritsuka and Olga Marie couldn't help but smile wryly, but they decided to ask Caster for more information. He was the first proper Heroic Spirit they had encountered, and they believed he must have some information about the anomaly.

First, they explained their situation. Ritsuka was conducting on-site investigations as a Master, while Mash had become a Servant. OmegaMon had become Ritsuka's partner Digimon.

"That holy knight over there is called OmegaMon, a species called Digimon, huh? No wonder I sensed a different aura from him compared to us Servants. It wouldn't be strange if he possesses the power of divine spirits."

"Caster, are you the only survivor among the Servants summoned in the Holy Grail War happening in this city?"

"Well, if you mean I haven't lost, then yes."

As Caster answered OmegaMon's question, he began to talk about the anomaly occurring in Fuyuki City. The Holy Grail War that took place there had somehow been replaced with something else.

The details were unknown even to Caster. Overnight, the city was engulfed in flames, humans disappeared, and only the Servants remained.

In the midst of it all, Saber restarted the Holy Grail War and went on a rampage. Lancer, Archer, Rider, Assassin, and Berserker were defeated. Caster managed to survive, but the defeated Servants were all contaminated by black mud.

Now, they were searching for something together with skeletal soldiers. Caster was included in the search. As long as they didn't defeat him, the Holy Grail War wouldn't come to an end.

"Thank you for the explanation. So, defeating the remaining Saber would end the Holy Grail War in this city, right? Regardless of whether the situation returns to normal..."

"You want to defeat Saber but can't do it alone, so you want to cooperate with us, is that it?"

That's right. Sorry. If I were summoned as Lancer, I could have finished Saber in one thrust... But, well, Caster doesn't really match me. I can't afford to be a Caster in the Holy Grail War in Fuyuki, seriously."

Caster was not acting for the sake of OmegaMon and the others but for his own objectives. It just happened to align with their goals.

Like Caster, some Heroic Spirits possess multiple Class characteristics. For example, the famous Greek hero, Heracles, has all Class characteristics except Caster. However, the class where he can exert his full power is Archer.

In Caster's case, he also has the aptitude for Lancer. Although he insists that his favorite and true calling is Lancer.

(He can use a spear and perform magecraft... I wonder who he is? If I knew his True Name, he must be an incredible hero.)

"As a rule for Servants, we shouldn't get deeply involved in matters outside our own era. We should only cooperate in battles. You want to investigate this anomaly, and I want to end this Holy Grail War. Our interests align. How about joining forces?"

"I want to do that too, but who will be your Master?"

"Well, it's obviously that guy over there. It's a contract limited to this city, but I'll rely on you, okay?"

Thus, with Caster joining OmegaMon's group, he formed a contract with Ritsuka. It would be until they investigated and eliminated the anomaly in Fuyuki City, so to speak, a temporary alliance.

Having a fellow Servant on-site was truly valuable. Not only did it strengthen their combat power, but they could also learn more detailed information.

"Now, we just need to confirm our objectives... What you guys are searching for will undoubtedly be the Greater Grail. The Greater Grail is like the 'heart' of this land, so to speak. If you hear about a singularity, there's no other possibility. But the Greater Grail is occupied by Saber, and the remaining contaminated Servants."

"Rider and Lancer have been defeated, so what about Archer and Berserker?"

"I can manage Archer as long as I'm here. Berserker is a tough one even for Saber, but if we don't approach him, he won't attack us. I'll be the guide. The timing of the assault is up to that guy."

Following Caster's guidance, OmegaMon and the others set their sights on the Greater Grail. OmegaMon immediately grew to a massive size, carrying Ritsuka, Mash, Olga Marie, and Caster.

As they began to move with low-altitude flight, Caster couldn't help but be surprised when he realized that OmegaMon could fly and freely change his body size.