Harry, thanks to his Master of Death Powers, had a major power boost to his magic. He could even use the Shinobi Jutsus, which the other Wizards just couldn't do.
Wizards needed a magical focus, AKA a wand, to use their "Chakra"... while Shinobi naturally had their own hands and feet, acting as the focus. While the Clans with Bloodlimits, had additional focuses built into other body parts.
Harry could use any Jutsus, or even the other clans' Bloodlimits, as spells. As his whole body had become a focus.
In addition, and something he found quite useful, he could teleport anywhere on the planet... even if he had never been there.
Apparently, "Master of Death" was a jurisdictional thing. He was the Lord of this planet's Reapers... chosen not because he found all the Deadly Hallows... but because he had them, and rejected them all.
So the Shinigami, the god of death, watching over Earth, chose him as a companion. Simply because he proved he wouldn't abuse that power.
• 5 years since the Supers and Magi came back to the world:
Gaara walked with his Uncle, down the streets of Konoha. His father had deemed him a failed experiment, even a threat to the Sand Village. So the Kazekage had gifted the Jinchuriki to Konoha.
On Gaara's first night in his new village, the Konoha Seal Masters... fixed his Seal. Rather, They put an additional Seal on his Forehead. The way the symbols were placed on him, it looked like he had a heart, above his left eye... it was even painted red.
Unlike the Kyubi, who volunteered, the one tail was sealed due to his violent nature. Shukaku, The One Tailed Beast, was a vengeful demon, filled with bloodlust, and a taste for human meat.
So the Seal Masters stopped the demon from being able to whisper into Gaara's mind, and blocked it from transfering it's bloodlust into the boy.
The modified seal, also allowed the boy to finally sleep. Something that used to Unleash the demon. So throughout the boy's life, he'd only gotten a total of 2 hours of sleep... with the few instances resulting in Shukaku attacking Suna.
So Gaara, after 5 long years of deprivation, was finally able to sleep to his heart's content. There was no longer a threat of his demon coming out. Obviously, this meant he spent his first week in Konoha, doing little more then sleeping and eating.
But now, finally feeling well rested, Gaara decided to explore his new home. First Stop? The Jinchuriki Estate.
It was a large Dojo, resting at the base of "The Twin Clans' Mountain" (Where the Supers and Magi Clans resided).
The Dojo was decently sized, with 200 acres of training grounds. With the building itself holding a grand design. With statues and carvings of the 4 demons of Konoha. They had already added Shukaku, to the architecture.
When Gaara was first brought here, he was told the Dojo was built by the Wizards, using their magical building techniques. It also used their knowledge of the "Extension Charms" and conjuration magics, to give them their own "Room of Requirement". So people could conjure endless rooms, filled with anything the Jinchuriki could need.
This estate was designed special, for the Jinchuriki to not only train, but socialize. Complete with home theater, and water slide into an indoor pool.
No Jinchuriki actually lived here, but their were 13 chambers. Each with 4 bedrooms, a lab, and a private Game Room. Enough for each of the Jinchuriki's future Shinobi teams, to have their own home away from home. As well as any guest teams, they may allow in their Dojo.
The Dojo was kept clean by the Estate's own House Elves. Magical servants, the Magi taught the various Seal Masters of the world, how to brew them through a potion.
The Seal Masters had been selling the House Elves, along with the other Magical crafts, for years now. Even in the Mist Village.
They were House Keepers, that got off on serving a Family. While their fair treatment, was added to the Doctrine. Hermione-Sama insisted on that, before allowing her clan to upload the knowledge, of how to brew House Elves.
Harry "Bloody" Potter's own elves, often helped maintain the Dojo. So Gaara was told, he'd see the Lord of Death, fairly often. He just wasn't expecting it so soon.
The moment Gaara entered the Dojo, Harry was smiling as he walked the other Jinchuriki through using their unique powers.
The Uchiha was channelling his serpent demon, to summon and command a variety of regular snakes. While the Kyubi's host, was doing the same with foxes. Then the host of the Manhattan Demon, was practicing Alchemy without need of runes.
"Take 5 everyone," The Avatar of Death, smiled at the ginger. Before Harry walked over to the boy and his Uncle.
"Good to see you again," Harry quickly shook the man's hand. Then returned his gaze to the ginger. "And you must be Gaara. Good to see you up and about." He attempted to ruffle the boy's hair. Only for the sand, that coated the boy's body, to lash out at the Avatar of Death.
Harry pulled his hand back, the sand instantly settling. Thankfully, he didn't look frightened... rather... concerned.
"I thought the Seal Masters were able to contain the demon?" Harry worried.
Yashamaru smiled, "That wasn't the Demon." He laid a gentle hand on the boy's head. The sand making no move to stop him. "That was his mother. She infused her soul into the boy, while dying in child birth."
Harry gave a small smile, a sad smile, as he remembered something. "My own parents did something similar. Merlin help us from over protective mothers."
Yashamaru gave a light chuckle. Before growing more serious. "With everything Rasa did, for the sake of his Jinchuriki 'experiment', you can't really blame my sister for being overprotective. Don't worry. Once Karura is sure you won't hurt her son, she'll allow you to touch him."
"Roger that," Harry gave a playful English salute. Then looked at Gaara, "Well my boy. Want me to teach you how to tame that sand of yours?"
• A Few Hours Later.
"The Shinobi Academy will be accepting students next month." Harry explained to his tired students. "Will any of you be attending?"
Gaara blinked, "We have a choice?"
Harry frowned, "Of course you have a choice. Minato couldn't force kids to join the army...that was more my own mentors thing." Thinking back to Dumbledore.
Harry loved the old man, but the whole reason he didn't have an issue with the future's use of child soldiers... was because he had been one, himself. At least the Shinobi had better training programs, and safety nets set up.
"You're mistaken Bloody-Sama," Yashamaru used an honorific, in addition to Harry's Shinobi nickname... which, despite trying to be as respectful as possible, made the Avatar groan.
Regardless, Yashamaru continued. "Jinchuriki are considered too dangerous, to allow them to skip out on the Academy.
"Most Villages don't even give them a rank, instead using them as weapons, outside the traditional chain of command. While Konoha honors them, by allowing them to ascend through the proper ranks, they nearly always join the ANBU, once they reach adulthood."
Harry stayed quiet, for far too long, in an uncomfortable silence. Before only saying, "I see..."
He thought he was just teaching them control. Due to his instinctive knowledge of how magic worked... but no. Minato had requested him, because he could turn the children into killers... there was only one thing he could do. His "saving people thing" compelled it.
• That Night, in the Hokage's Office:
"You sure about this?" Minato asked. Harry had appeared into his office... and made, a tempting offer.
In exchange for allowing him to become the Jinchuriki's Sensei, after they passed the Academy, Harry "Bloody" Potter...would finally allow himself to join the ANBU. Something Minato had been trying for, since the Hokage saw Harry in action, against Madera.
Saitama had been easy to convince, as he longed for a challenge... but Harry claimed he was "retired from Hero Work".
"A team of Jinchuriki, would be seen as a high priority target. I had planned to split them up, once they graduated. With one Jinchuriki per team."
"I can keep them safe," Harry assured.
Minato studied him. Then pushed more, testing his resolve. "Typically, a team is made up of three Genin, and one Jonin. While there is no question, you meet the requirements for Jonin, there is a reason we limit the kids to 3 to a team. Any more, and in fighting becomes more likely, along with their Sensei not able to give each Genin the attention they need."
Three more Harrys suddenly stepped out of the original. There was no hand seals, nor smoke. They just walked out of him... this was more complicated chakra based clones, then even The Shadow Clone Jutsu.
They were clearly solid, clearly guided by the user's subconscious, but they each had the same amount of Chakra as the original. The caster sacrificed nothing... that's when Minato realized, They weren't temporary Chakra constructs. They weren't Constructs at all. Harry just willed three flesh and blood bodies into being, all guided by the same joint conciousness. Sharing a soul between them.
Minato did his best to not react, not even to gulp, as he desperately wanted to. It was hard to remember. Harry was no ordinary wizard, but a muse for a true god.
"New trick?" Minato just raised an eyebrow, and hoped it looked unimpressed.
"Got the idea- after fighting with Madera- that kid's clones seemed useful- but figured they could use an upgrade." The clones took turns talking. Watching them was a bit like a tennis match.
Then the clones calmly stepped back into Harry. Seamlessly being reabsorbed. Once they were gone, Harry insisted. "You could give me a thousand kids to train, and they would all receive one-on-one personal training, in addition to team work exercises.
"Plus, due to the demons they contain, they can be taught most of my spells. Even my Flesh Clones, and World Wide Teleportation. Although those are more advanced spells... imagine what you can do with 5 of me?"
Minato gulped. He was thinking of it... and it was hard enough to convince the other villages not to attack, after absorbing the Mist Clans. If they ever found out everything Harry could do... war would be inevitable... but if war was coming, he should prepare for it.
Madera clearly wanted a war. And Kiri was itching too prove itself. Prove it didn't need bloodline traits... all appeasing the other clans had done, was buy a few more years of peace... but he would make use of those years. Forming alliances, while preparing for war. Hopefully, if he played his cards right, it be 41 villages, against Kiri.
The cloned clans, were based on Minato's own scrambled genetics. As he wouldn't have asked another, to do something he was unwilling to. so maybe they would still have his desire for peace.
They were his opening, to unite the villages, by more then a flimsy doctrine. They might be able to have a proper country again. Obtained by diplomacy... that was Minato's dream...
But too inspire such, Konoha would have to remain a force of strength. Somewhere the other villages could respect, for both their attempts to preserve peace, and their military might.
For that, he needed trump-cards of his own. The most powerful supers, were police, not warriors. He couldn't use them in any military battles... and wouldn't want to force the issue.
The magi were more willing to kill, but were glass cannons.
Harry, and Jinchuriki trained in his techniques, were their best bet.
"I can't make you their Sensei," Minato insisted. "As that really would make you too large a target. But I can grant you the rank of 'ANBU Captain', and put all four of their future teams, as your platoon.
"It isn't often, teams with Genin are assigned to a Captain. But it's not like it never happens, with high priority trainees. No one will even question, you giving specialized training, to the Genin under your command.
"Accepting this position, will cement your authority over the kids. Giving you a say in their missions. Such as the option to decline missions, on their behalf. Provided we aren't in a state of emergency.
"Until the kids graduate, you would work for our black-ops, gaining experience in the field. Occasionally leading teams of Chunin. Until you've proven you can handle teams for S Rank missions. All that sound fair?"
Harry thought on it. It wasn't exactly what he wanted, but he was willing to compromise. "Works for me. When do I start?"
Minato was silent for a moment, as an idea formed in his mind. It be risky, but he'd seen the Wizards invisibility Jutsus at work. And Bloody-Sama was known amongst them for his Mastery of Stealth.
Minato couldn't afford to delay, not even to field test the man. Besides, it wasn't like Harry could even die. There were various immortal Shinobi, all of whom were of incredible power. So, as Hokage, Minato would have to risk it. He'd have to throw Harry into the deep end... and hope he didn't trigger the war before they were ready.
"I have your first mission in mind. As, until now, we lacked anyone with the skill set to pull it off," Minato studied the century old young man. "I need you to steal all summoning contracts from Kiri. And most importantly, leave no evidence that Konoha was involved.
"Then distribute the scrolls to trusted Shinobi, from all other Hidden Villages, but leave Madera's Fox contract in Konoha. That should throw off any suspicion, while protecting the demons."
Harry frowned, thinking on it, "So I'll need to sneak into, not only the most well guarded vault in Kiri, but pickpocket Madera... won't be able to risk being seen, much less a fight. Then will have to conceal my identity, when delivering the scrolls..." Harry slowly smiled. "I haven't had that much fun, since I broke into Gringotts."