The invisibility potion
In the room of requirements, every night Anthony would practice Wandless magic, Occlumency, and Parseltongue magic.
Anthony has already purified Ravenclaw's diadem from Voldemort's Horcrux. When trying on the purified diadem, it had some refreshing abilities that allow him to focus on study, but not it has not powerful magical ability to become a genius. Therefore instead of becoming a princess that wears a diadem, he decided to drink his Lightning beverage to enhance his mind.
Even with the aid of Occlumency, the most difficult part of Parseltongue magic was to distinguish between English and Parseltongue. It required him few days to adapt to know which language he was speaking in.
sss"Reducto"sss said Anthony in Parseltongue. The wooden dummy in front of him shattered into pieces as if being pressed down by a car.
sss"Fantastic"sss said Anthony, "Oops, still in Parseltongue" muttered to himself.
'Parselmagic is somehow around 2 times more potent than Latin magic. And my basilisk horn core wand is fully synchronized with it. Even though I am not capable to defeat adult wizards yet, If I use parselmagic when they are careless, I may be able to win. So he decided to hide his ability of Parselmagic and use it only in dire need.'
"Gormlaith Gaunt, older sister of founder of Ilvermorny Academy of Magic. You have left me a very useful book." Anthony said to the notebook that contained Parselmagic. The notebook described numerous ways to utilize parselmagic.
Anthony went to the Library and searched about Gormlaith Gaunt and found some interesting stories about the owner of Parselmagic notebook. She was an extremist of pureblood supremacy so much that she killed her brother-in-law and husband when they showed pity towards their muggle neighbors. In the end, she was killed by her younger sister after a duel between them. Gormlaith's niece also refused to become a mother afraid of having a son or daughter so terrible to inherit talent in parseltongue and become like her aunt. Therefore she ended the Scottish lineage of the Gaunt's family, and leaving England's lineage alone in the World.
But for Anthony, it is not a sin for him to utilize parselmagic. He understands that it the wizard who is evil, not the magic.
On the 28th of September, 1991
Slytherin students became the first loyal purchasers of the Lightning drink, when giving back the bottles to Fred and George, they are reimbursed with 2knuts. Soon students in the fifth grade and seventh grade who shall take the Ordinary Wizarding Level (O.W.L) tests and Nastily Exhausting Wizarding Tests (N.E.W.T) at the end of the year become hardcore users of Lightning drink.
The benefits of becoming focused refreshed and having less fatigue is giving them more time to study for their tests. After the patronage of upper grade students, the entire Hogwarts castle began to drink the lightning beverage daily.
Unfortunately, Since Harry, Anthony, and Daphne couldn't brew around 500 bottles each day, Anthony asked Randolph to hire potioneers to brew Lightning beverage and deliver it to Hogsmeade, and stopping the distribution to Hogwarts.
Soon, in Diagon Alley, a new drink called Lightning has been born and become as famous as butterbeer. It has a taste similar to muggle canned soda but gives refreshing effects that relieves fatigue and gives enhanced focus. The bottle had a lightning bolt logo, with Harry Potter's picture that is holding the lightning bottle on a firebolt. On the bottle's tag, it says "Harry Potter's invented drink". Even though it is somehow misleading, Anthony and Harry are owners of the Lightning beverage patents, registered at the Ministry of Magic.
Since there are many books that exaggerate about Harry Potter, the poor wizarding community bought the idea of Harry being a potions master and the inventor of Lightning beverage. To repay the debt of salvation from Voldemort, many adult wizards prefer the Lightning drink themselves.
The first 25000 bottles have circulated in the first week among Diagon Alley, Hogwarts, and Hogsmeade. Harry Potter got 400 galleons dividend, Anthony got 400 galleons dividend, even though Daphne refused to get money, eventually, Harry and Anthony insisted to gave Daphne 200 galleons as salary for her hard work and persuaded her. Fred and George got 263galleons and 10 Sickels galleons for distributing around 5000 bottles of Lightning beverage in Hogwarts.
Anthony stopped the distribution of the drinks in Hogwarts by the 1st of October,1991.
The invisibility potion has been brewed, and Daphne, Harr, and Anthony was standing in front of the cauldron putting the potion in 3 bottles.
"Finally, the invisibility potion is brewed," said Anthony and the three friends become happy, hugging each other.
"Thank you Harry, Anthony, if it weren't for you guys, I couldn't brew this potion alone. Also, I have learned a lot during the past few weeks about potions!" said Daphne.
"You are welcome, what are friends for? But Daphne, since you already have the invisibility potion, what are you going to use it for?" asked Harry with a curious tone.
Daphne become a little bit gloomy but replied "Harry, Anthony, the thing i am going to tell you is a bit secret. But I have a younger sister named Astoria and she is terribly ill. She has a bloodcurse that is called Maledictus" said Daphne with a weak voice.
"Maledictus? What is that Daphne?" asked Harry.
"Harry, Maledictus is a blood curse that turns a woman eventually into a beast permanently. And my sister's Maledictus is a Panther Chameleon with a limited 1-year lifespan. Whenever she turns into a Panther Chameleon, she would lose a lot of her lifespan. So I want to help her by finding a way to cure her maledictions and I want to enter the restricted section of the library with the invisibility potion" said Daphne and she immediately cried after.
Harry, and Anthony consoled her and decided to go with her together to the Restricted section.
"Daphne, since there is enough Invisibility potion, we would help you to find any clues in the Restricted Section of the library," said Anthony.