Anyway, after beating the shit out of each other and realizing, yeah, they were about equal in strength—while Aizen may have had more chakra and raw power, Seijuro was way faster, and his mastery of the Flying Raijin was above Aizen.
He could use it in such a way that he could be in five spots at the same time—existing, yet not existing at the same time. Using the Flying Raijin, he could create echoes of himself—past versions—and have them fight his opponent for him.
Yes, this was a brand new level to the Flying Raijin.
So yes, they were practically equal.
Aizen would need to fuse with Seijuro before absorbing the Ten Tails, just in case. He could have absorbed it without Seijuro's help before, but his ass went and kinda made the Ten Tails... like 100x stronger than it should be. Not just 70x, but 100x—so yeah, he needed his other half in order to make sure everything went smoothly.
As for where the fuck he was keeping the Ten Tails... another dimension.
Speaking of which, in said other dimension, he was now with Seijuro, lab equipment all around them. Some failed experiments were there, collecting data only...
Seijuro laid eyes on Aizen's prized possession...
The Synthetic Ten Tails.
Not a natural beast. No divine comet-borne horror like the original.
This one was engineered—painstakingly built from fragments of the original's DNA, sealed bijū essence, chakra fossils, Hashirama cells, and a lot—and I do mean a lot—of artificial bijū chakra.
It wasn't perfect.
But it was close enough.
"Stabilization's going well," Aizen murmured, pressing a gloved hand to the console nearby. "In a few years... it should be combat-ready. Fully weaponizable."
Seijuro folded his arms, eyes fixed on the grotesque yet awe-inspiring beast. "And what's the plan with it?"
Aizen tilted his head slightly. "Once it's fully developed, ideally, I fuse with you, and we seal it inside ourselves. We'll need a lot of time to fully be able to manage all of its chakra—but once that is done, its power is ours."
Seijuro didn't respond. He already knew what that implied.
So, after it was done—fusing—and then, god-like powers.
Yet the closer it got to fusion, the more he felt like those pesky Ōtsutsuki would show up again in the future.
Oh well, this was Aizen's own personal dimension.
The beast should be safe here.
Should being the key word.
"I also may or may not have injected the chakra of the beast into a little poison, which in small doses does nothing—but considering how much chakra it has, it has enough chakra to kill someone like Hashirama... 10,000x over. Made it Ōtsutsuki flavor."
"I'm assuming if the person absorbing the chakra isn't you or me, the poison affects them," he said calmly.
"You are correct," Aizen replied just as calmly. This was his anti-theft device. Quite nifty, if he said so himself.
He gestured to the nearby table, where a small, fist-sized device sat. A faint spiral glowed at its center—blue and red, shaped like a distorted Karma mark.
"Pseudo Karma."
Seijuro arched an eyebrow. "Oh, so you actually worked on those," he said softly.
"This one doesn't use Ōtsutsuki power," Aizen explained. "Instead, it's synthetic. Think of it like a condensed, renewable bijū chakra core. Inject it into the host, let the mark imprint, and you've got something approximating a jinchūriki—without the beast."
"Side effects?"
"Unknown. Still running trials. But theoretically... it regenerates itself. Boosts healing. Vast chakra reserve. Reflex enhancement. Partial transformations. Could simulate the strength of the Nine Tails at peak."
Seijuro let out a low whistle. "And I'm guessing all that chakra would come from... it."
Aizen smirked. "Exactly."
They moved toward the far side of the lab, where test tubes lined the wall. Floating inside them were strands of tissue—some clearly Senju in origin.
Hashirama cells.
Aizen checked a nearby clipboard, scribbling notes. "Still temperamental. But usable for bonding tissue with the Karma prototype. I've got a few candidates I'm considering."
He tapped another tube, this one marked with a complex symbol—a genetic marker.
"Also," he added, turning back toward Seijuro, "your blood helped quite a bit."
Seijuro frowned. "Meaning?"
"I ran a full analysis last night. You're now roughly seventy-five percent human... twenty-five percent Ōtsutsuki."
"...Hm... that's lower than I expected," he said softly.
"So did I. Your soul completely destroyed the Ōtsutsuki living within that mark. Its power is basically yours."
"Hm."
He looked almost pleased.
"Progress is beautiful."
Seijuro approached the tank again, his reflection barely visible in the fluid's surface. He gazed at the beast inside—the ten-tailed weapon of a new generation.
It twitched again, as if sensing him.
Everything was moving forward.
Faster than he expected.
More dangerous than he'd hoped.
But he didn't flinch.
He just stared. Quiet. Thoughtful.
Once he reached this step in the path... what lay next in his route to absolute power would be the Ōtsutsuki plan.
They had to be wiped out.
A/N....a ten tail like 100x time stronger, that easily above Ishiki level, but be happy since his body cant handle that much power, he will have limiters on...like code, to help him get use to the power, so the ten tail will start off, at what it was in canon in term of power, so his boost in power, should roughly land his power on Kaguya ish level, he will need it....Stronger Otsutsuki are coming.