Chapter one (HPOCSI1)

Joe, our depressed main character had finally achieved his goal of dying... but only because human beings were all idiots. Yes, he was killed along with all of humanity in a stupid nuclear war. Most of humanity, each in their different countries, had all decided to vote for idiots; greedy idiots, warmongering idiots, idiots with moronic political and religious ideologies, and incompetent idiots. Any idiot could get elected if they said all the right things. Our main character knew this because he ran for mayor and then won the election and the re-election. Not bad for a high school drop-out, huh?
"Yes, you did have a pretty disappointing life," a mysterious voice spoke.
"It could have been worse," Joe, the main character returned.
"Yes... you mostly spent your life pursuing your dreams while working other unfulfilling jobs and helping out your family. We pity your sucky life and that's why you can have a second chance... with unique powers in another fictional universe."
"Unique powers? That's a very vague." Joe replied.
"It's that or purgatory though."
"So, what are these other universes available?" Joe asked, not liking his other option.
"Game of Thrones, Star Wars, Harry Potter, Pokemon, Percy Jackson and the Olympians, Dragon Ball, Avatar: the Last Airbender, and the MCU."
"Well. I wouldn't wanna live in Westeros or Essos, the gods in PJO can one-shot me, and as a human I'd still easily die in Dragon Ball or quickly become irrelevant, the MCU has too many huge threats, and that just leaves me ATLA, Pokemon, and Harry Potter... I think that I'll go with Harry Potter, even if I dislike J.K Rowling's choices and all the power of love crap. It was more like Dumbledore guiding a lackwit hero to where he wanted him."
"Good," the voice replied. "Pick a family in Harry Potter and no you can't be a canon character, but you can influence them or marry them."
"Will there be nobility, awesome rituals, and emancipation?"
"Yes," the voice answered.
"Can Harry Potter be a girl instead?"
"Fine, but use protection when you try seducing her."
"Can I grow into an identicle or larger penis size; girth and length?"
"Fine. Now choose your family."
"I choose House Black," Joe replied.
"Good. You will have Sirius Black as a father and Marlene McKinnon as a mother and you will be born on April 1st, 1980. You just need to pick your boons." Having said that, the being manifested a list of boons that Joe viewed.
Quite a few stuck out to Joe and he selected...
Magical Prodigy: You have far more magical potential than most and in fact have the potential to be one of the strongest of your time. You have an intuitive understanding of magic and you can easily grasp advanced concepts that would stump others and quickly master spells, potions, and rituals and alter pre-existing spells on a whim.
Magical Potential (Legendary): Magic is but a muscle to be exercised and you have far greater base magical power than most. This boon allows you to reach the levels of Dumbledore, Voldemort, Grindelwald, or even Merlin and Morgana with training.
Ambidextrous: You can naturally and effortlessly use each hand with equal skill.
Eidetic Memory: Perfect recall.
Metamorphmagus: Can take virtually any form with practice.
Natural Legilimens:
Natural Occlumens:
Strangely some boons were already pre-selected...
Magic Draining: Can drain magic from people with weaker magical power. Draining them completely leaves them a squib.
Life-force Draining: Can drain life-force from lifeforms with lower magical points. Draining them completely kills them.
Magical Prodigy gave him the potential to be at Dumbledore's, Voldemort's, and Grindelwald's levels and Joe didn't wanna suffer or die due to their incompetence, insanity, or ambition. Ambidextrous ensured that he could switch hands in duels, Eidetic Memory meant that he could retain everything that he learned, being a Metamorph was good for hiding or correcting any physical flaws, and Natural Legilimency was incredibly valuable.
All of the boons reminded him of gaming perks.
"How the hell did I get the ability to drain magic and life-force?" Joe asked in shock.
"Because you technically figured out how to while writing fanfiction," the voice replied. "You can't absorb spells and such though. Congratulations, Joe. You are now done with your pre-birth choices."
"Thank you," Joe replied. "What now?"
"Now you are pushed out of a womans vagina and then named," the voice replied mockingly. "Don't worry. I'm forbidden to enhance your poor infant eyesight so that you can see your new mommies baby chute as a joke. Anyway, you'll survive when the entire McKinnon family is wiped out and can take the opportunity too drain Crabbe and Goyle Senior of magic and life-force... they are the only two Death Eaters weak enough for you to drain. Inbreeding does take its toll; especially when its coupled with laziness and stupidity, and they are slightly weaker than your infant level of power."
"So by draining magic and life-force I can avoid training to greater magical power and even lengthen my lifespan?" Joe asked.
"Yes. Up too centuries, but you should only use that ability in life-or-death combat. Anyway, prepare yourself for the squeezing sensation of being born."
----
Being born while cognizant was extremely uncomfortable, but Joe was soon renamed Perseus Arcturus Black by his mother Marlene McKinnon-Black... apparently Sirius Black had married her, which increased his sons opinion of him.
"He's utterly perfect, just like his mum and dad," Sirius commented in mild humor, annoying Lord Michael McKinnon.
"At least you married her," Michael commented, pleased that Black at least had the decency to do that.
"Well, yeah," Sirius replied sheepishly. "I needed to protect our child from bastardy, and both families and ourselves from public shame. Besides, now I can pass on my demigod-like pranking skills onto another. Soon the Marauder Legacy will be secured with a next generation... Prongs and Lils kid will be born soon enough."
"How would you like them to be Perseus' god parents?" Marlene asked, being quite close to Lily.
"Of course! I'd love that!" Sirius said, before kissing Marlene passionately and causing her to giggle.
None of this joy would last very long.
Death Eater's would attack them ten months later and Perseus would drain both Crabbe and Goyle Senior of a lot of their magic before his mother sent him to safety via a house-elf before Severus Snape could cast a Killing Curse on him. Perseus would lose all of his family because of the Death Eaters and he would vow revenge. Having few options and unable to think clearly, the house-elf would take Perseus to Walburga Black and would then be rewarded with a Killing Curse for its trouble...
Percy would be raised by her and several other members of House Black as a Dark Wizard as revenge for Sirius' betrayal... Sirius would never learn that his son still lived before he was imprisoned in Azkaban. The only thing saving him was Arcturus Black learning of him and using his powers as Lord of House Black too force them to treat Percy right instead of killing him to guarantee Regulus inheriting the Lordship.
Percy was still forced to learn magic once he could walk and talk... which was both a gift and a curse. A gift because Percy would begin learning Occlumency, the Dark Arts, Defence Against the Dark Arts, Potions, Charms, Transfiguration, History of Magic, Ancient Runes, and Astronomy.
Percy began training his Occlumency constantly while reading, studying, and magically experimenting and performing Occlumency exercises routinely... by the time Percy was five years old and Walburga had died he would have mastered Occlumency and would be very gifted in magic. Percy was displeased that was all he had after five years of intense work.
Percy was thankful that Lord Arcturus Black was far more demanding of his only remaining viable heir and wanted his future secured.
Percy was taught by Horace Slughorn in Potions and Lord Black in the Dark Arts and their defence... that Magical Prodigy boon and Eidetic Memory boon served him extremely well in those tough lessons. Percy would become an expert in the Dark Arts in two years of near constant study under Lord Black and self-study.
----
Perseus Black was now seven years old and had been formally named Heir Black...
Thankfully by this time Percy had located the Locket horcrux and he had probably the most interesting idea ever...
Become Lord Slytherin by Right of Conquest.
All he had to do was destroy three horcruxes.
Thankfully Arcturus believed that his grandson and Heir needed to be involved...
"I wonder if the soul fragment could have its inherent magic absorbed and be dispersed into the afterlife?" Percy questioned aloud, drawing his grandfathers attention.
"You can try it so long as I'm in the room and only if you don't touch it," Arcturus said, intrigued by the possibility.
Percy nodded, pleased and pulled on its Magic...
"It's done," Percy said, pleased with his success.
"Good," Arcturus replied, after confirming his heirs words.
"Is there anyway to check out the Lestrange Vault since they're in Azkaban? Any clauses in a marriage contract or something?" Percy asked, causing Arcturus to become thoughtful.
"There should be an unfulfilled child requirement," Arcturus mused, summoning the contract. "Ah, there it is. Should the spouses fail to conceive a trueborn heir within seven years then the marriage shall henceforth be annulled with House Black free to reclaim the dowry and any allowances plus interest... the percentage was wisely undefined by my son. Penalties for dealing in bad faith are viable, penalties for damaging the good reputation of House Black... yes, we can seize House Lestrange's wealth. All of it, in fact."
"Can we go to Gringotts soon?" Percy asked. "I'd like to do a heritage test and ensure that I can have every financial or political advantage, and also claim the Heirship for House McKinnon."
"I see no reason not too, we have much to gain," Arcturus replied.
Hours later...
Seizing House Lestrange's wealth and bribing the goblins into silence with all goblin made objects within the vault kept everything nice and secret, giving them years or more to avoid any fallout.
The heritage test, that was interesting. The Black's were related to Raczidian and Ekrizdis, and could lay claim to the bastards assets... they were literal bastards and had produced no heirs. They were also related to the Irish branch of House Gaunt... which was interesting to Percy. Percy had also claimed the Heirship to House McKinnon, but it wasn't very wealthy.
With the horcrux in their possession, Percy drained it of magic.
Now they simply had to locate the others and cleanse them, but Percy would still focus heavily on improving his magical skills and knowledge.
----
Percy was eight years old now and he was at NEWT-level in DADA and Potions. Percy was extremely pleased, but he knew that things would change at Hogwarts and that he would have far more challenges.
Until that time though Percy would continue gaining power, knowledge, and skill in preparation for those challenges...
Like retrieving the Resurrection Stone.
Thankfully his grandfather in this world was handling the wards at the Gaunt hovel while ensuring that the evidence of them being here was erased and that the wards would remain.
Percy peeled away the rotting floorboards, extracted the golden box, and then the ring... after stopping his grandfather from touching it.
"It has a compulsion and I think a Withering Curse on it, I'm not sure, but that's what I'm sensing," Percy explained. "Can you remove that curse?"
"Yes," Arcturus replied, proud of his heir for his mental strength and skill. Arcturus removed the curse, an act that took great amounts of power, and then Percy drained its magic. "Do it, my heir."
"I call upon Mother Magic to test my claim... I have destroyed three of Tom Marvolo Riddle's horcruxes, defeating him thrice, and I call upon thee to grant me his assets and titles as spoils of my victory..." Percy said before patiently waiting.
Percy felt a sudden influx of power and as if something within him were broken free and witnessed two rings appear on his hand. Unknown to Harry, the potential to speak Parseltongue was unlocked within him.
"The Resurrection Stone," Percy said, before putting it into his Inventory.
"Indeed," Arcturus replied, not caring if Percy concealed it for himself. He would be reunited with his family soon enough and he would leave the pursuit of supposed immortality and god-like power to his young heir. "Come, we'll cover our tracks and create a fake to deceive our enemies before we leave."
Percy nodded in agreement and they left, leaving behind a fake ring with the same curses on it, the same wards, and the same defenses for the Gaunt hovel.
----
It was soon time for Percy to take his OWLs in Defense Against the Dark Arts, Potions, and History of Magic.
Percy completed his OWLs very confidently and with very high expectations for himself. Percy wasn't even slightly surprised when he received all Outstandings on his OWLs.
The NEWTs were far harder, even with his Eidetic Memory and prodigious abilities, but Percy was thrilled when he achieved all Outstandings.
And now all he had to do was convince Horace Slughorn to take him on as his apprentice.
"Thank you for inviting me over to dinner, Lord Black," Horace said, politely. "The invitation was quite unexpected and I didn't have time to bring a gift with me."
"That's fine," Arcturus said, waving the concern away. "I've actually invited you over with a proposition in mind... You have taught Perseus about Potions from the basics to NEWT-level, and I was wondering how you would feel about continuing his teaching up to Mastery Level. You would be well paid, of course."
"I would love too! Perseus is a joy to teach and he has even taught me a couple of tricks." Horace said, unctuously.
"I'm pleased that you've agreed so easily. I don't have very long left and I'm taking measures to ensure that Perseus has plenty of power and skill and can avoid that Death Eater Snape's attempts to get revenge by targeting the son of Sirius. I'd rather that Percy not get in trouble for hurting him in self-defense. And he's testing out of incompetently taught classes to avoid wasting time or having a skill sabotaged." Arcturus said and Horace nodded in agreement, revenge would be highly likely given the treatment Snape suffered from the Marauder's.
"I'm free to begin his apprenticeship within a few days or as soon as its convenient for you both," Horace said.
"A few days would be ideal. Perseus hopes to achieve his mastery before Hogwarts and he is prepared to push himself extremely hard in Potions and a few other fields that catch his interest."
"And what fields of magic are currently catching your interest, my boy?" Horace asked.
"Rituals, Warding, Transfiguration, Soul Magic, and Enchantment," Percy replied.
"Two of those subjects are quite frowned upon, Perseus," Horace said.
"Yes, but my interests are largely academic and theoretical. Muggles have discovered cloning and I'm very interested in the possibility of enchanting a copy of myself to draw my soul into it like a magnet upon my death. It wouldn't require a mastery in Alchemy and knowledge known only by one person and it wouldn't require immoral applications of magic. It's literally creating an empty body to move into later. The field of cloning is decades away from being truly viably for humans, but so is what I'm calling Essence Transfer." Perseus explained, surprising and impressing Horace and Arcturus.
"I didn't know that muggles were capable of that," Horace commented in awe.
"Well they aren't yet, but by 2000 they should be experimenting with cloning humans. Regrowing body parts is theoretically possible too, but unlikely given the possibility that the body might reject cloned body parts. My goal is sustainable immortality without resorting to any immoral magic." Percy finished. Percy would also be researching the possibility of a Grey Horcrux by using Soul Manipulation to shave off 1% of his soul and then place it into an object. It was far superior to continually halving the soul until you had less than 5% of your soul left.
Percy had his first apprenticeship now and he was committed to intense studying and research until he went to Hogwarts.
Percy would end up spending years performing intense study, research, and training to attain new levels of power, knowledge, and skill. Percy had finally figured out how to drain life-force from targets with Blood Magic and could now control souls by analyzing the Arithmancy of the horcrux creating spell and the Killing Curse and then inventing the spell.
Between that, his apprenticeship to Slughorn, restoring Grimmauld Place, and his work on various magical skills, Percy was soon a very gifted young wizard.
Soon, Percy would start Hogwarts and then everyone would know of his existence, already Lucius Malfoy had tried acting as recent for House Black before being rebuffed by Arcturus who cited himself as still being alive and him having no interest in a descendant of an oathbreaking French peasant controlling his house and assets while he was still alive. Percy was Arcturus' secret weapon and an unpleasant surprise for his enemies who wanted House Black's hoarded knowledge, wealth, power, and influence to become their own families. Neither Percy nor Arcturus intended for that to ever happen... Percy was willing to kill off the entire Malfoy family too prevent them from ever giving Voldemort access to the library if they could. That threat needed to remain downgraded and not be helped up by weaklings born only to serve their superiors.