Anyway, he was here now for one thing only.
He now had a piece of all nine Bijū within him—not a lot, but a fragment of each.
He had been researching a way to create artificial Bijū chakra and had made some progress in it. The problem was... it was slow and very inefficient. Like, you'd have a better chance becoming a Jinchūriki than using this method—it took a couple years to even generate one tail's worth of chakra using it.
This could be easily fixed with the Grim Reaper.
He had about 200 or so Kumo shinobi captured—his snakes had done the work. More like, for every 10 shinobi they encountered, they captured 1.
And considering the thousands of shinobi the snakes had slain, having roughly 200 left wasn't such a big deal.
Anyway, he was inside an array. The area was filled to the brim with seals—very potent seals. He didn't mind them. They were there for the calibration, alongside other stuff.
The Hashirama Cells were also being used in this process.
Aizen glanced at the piece of the Gedō Mazō.
Hm. It wasn't that big, yet it was big enough. He had used Wood Release, alongside Hashirama Cells, in order to give it the size it had now.
He had also fed it a shit ton of Bijū chakra and nature energy, which seemed to bring it back to life... or closer to life would be a better word. It still craved more.
So, he looked at his artificial Bijū chakra machine. In it, he had chakra from each Bijū:
Kurama. Gyūki. Chōmei. Saiken. Kokuō. Son Gokū. Isobu. Matatabi. Shukaku.
Using the fragments of their chakra, he could somewhat mimic their energy.
Though the process was slow.
At this rate, he'd only be able to finish this in, like, 200 years.
And he didn't have that kind of time.
"Phase One... successful," he murmured.
This was evolution.
This was godhood.
He then looked at the notes that Seijuro had sent him.
A smile played across his lips.
He was amused—he should have expected nothing less from himself.
In his hand, he held the improved and more efficient version of the Reaper Death Seal he had used to awaken his Rinnegan.
Like, instead of taking one year per person, now it took... their remaining lifespan.
Hahahahahahah. He really shouldn't have expected anything less.
Though, it seemed like his other self hadn't stopped training either, as he was now a perfect sage—no, not like Aizen, but in the literal sense.
Seijuro was in a perpetual state... of being in Sage Mode.
Like, at any moment in time, he was in semi Sage Mode. He had found a way to fuse it with his chakra. And just like that, the gap between them was once again shortened.
A death match between the two of them wouldn't end well. Sure, Aizen had the Rinnegan, but Seijuro knew damn well his other self probably had plenty of seals prepared that could render the Rinnegan useless. Aizen wouldn't put it past him—after all, it was him.
Though not being able to trust yourself was quite sad, Aizen knew it wasn't a matter of trust.
It was a matter of making sure. Putting safety nets in place.
You can never be too sure with anyone.
Even yourself.
Plus, Seijuro was just making sure he had a switch in place, on the rare occasion that Aizen ever got taken over or some shit like that. While Aizen wished to relive those memories again... he felt that the life Seijuro was living was the reason they even existed in the first place.
Seeing the smile on the faces of those little Uzumaki children warmed his heart in a way he didn't even know could exist. As much as he planned to reach godhood... he felt lonely. The one person who could understand him was... living another life. And the only woman who could see through his lies and deceit was probably busy doing tricks on it.
[He's not wrong.]
He sighed.
Anyway, back to experimentation on human souls... yay. Not his first time.
He went through the hand seals, put on the mask... before summoning the Grim Reaper once more.
Once that was done, he summoned the living bodies of the Kumo-nin... and had the Reaper eat them.
With the newly improved technique...
After sacrificing 200 Kumo-nin... and giving away all of their remaining lifespan...
He watched as the small little piece of the God Tree (Gedō Mazō) began to change.
His brow furrowed, wondering what was causing it—it seemed to be turning into a seed, then slowly evolving into a tree. The chakra from all of the Nine Bijū began flowing into the beast—very, very slowly.
At the rate it was going, it would be done absorbing all of their chakra in a few months, maybe a year or two.
Once the process was complete... it would turn into what Seijuro/Aizen needed.
The Ten-Tails.
Which he would then absorb and become the Ten-Tails Jinchūriki.
And since, with all the shinobi he had sacrificed, this Ten-Tails should be far stronger than usual.
As in—his machines needed 200 years...
Four shinobi alone gave him that much...
And he had two hundred.
A/N This 10 tail is roughly 76X time the strength of the original one.
Base Assumptions:
Target lifespan: 95 years
Youngest shinobi: 15 years old → 80 years left
Oldest shinobi: 25 years old → 70 years left
Average chakra harvested depends on age group.
Now let's split the 200 shinobi into 3 general age brackets:
Age RangeEstimated CountAvg. Lifespan LeftTotal Time Gained15–1760 shinobi~80 years4,800 years18–2180 shinobi~76 years6,080 years22–2560 shinobi~72 years4,320 yearsTotal200—15,200 years🔢 How Much Chakra Is That?
Aizen's synthetic chakra machine needs:
200 years to generate one full batch of chakra from the Nine Bijū fragments (equivalent to canon Ten-Tails full chakra).
Now, divide the total time gained:
15,200 years ÷ 200 years = 76 full batches of Bijū chakra ✅ So the synthetic Ten-Tails Aizen is making will have:
⚠️ 76x the chakra of the canon Ten-Tails
(Roughly equivalent to 76 Ten-Tails worth of chakra)
I am going with the lower end of this, higher end look like 80 to 85 time canon....which could technically be reached...no one said that Aizen needed to stop at 200 Shinobi...why not a thousand....
Tldr, this ten tail, will be powerful, and funny thing is, not an ounce of will in there, or self awareness, just power, ready to be used.
As for anyone saying what about the otsutsuki wouldnt they sense it and try and steal it.
Yes and no.
Yes they will be able to sense it, no a certain sliver hair god is still protecting him.
So chance are they probably sense it when it's done and even then only one of them would be allowed close the other will have worse direction sense than Zoro.