Time Travel Attempt
After he had finished the activation seal and brought back the books, sasuke concentrated hard on adjusting a seal to a human.
He had long since dismissed the bins seal- one chakra book talked about how they were very different. Biju had a cinciousness. Chakra remains humans had left behind hadn't. Biju could show and change emotions and the chakra in the artifact would either be led by instinct ( because, again, chakra is weird) or not react to anything at all ( unless someone knew a jutsu for that).
In the end Sasuke designed a seal that could be described as " a storage scroll with a hole in it. " The seal was small enough that it didn't really matter where he would put it and, theoretically, he should be able to
access it. He coukd only try that once he tried it.
For a similiar reason, he worked on how to pry chakea out if objects to ensure that he wouldn't have much trouble.
Besides that he kept up his usual training regime mostly for the watchers, went to school and practiced sensing on the way ( he was far from good but at least he could feel something) and then went home to read, mark important things, read those with his sharingan until his eyes bled and continued on.
He also, under a henge, managed to bring his will to a lawyer and ensured their loyalty to him by giving them 20 Tim's the appropiate money.
After Al, the village wouldn't get Uchiha land even if Sasuke died or went to another timeline and never went back. Instead, Sasuke had given absoloutely everything in case of their demise to the cat clan his clan was allied too. After all, they deserved the financial support, normally hot it at least once a year and if nobody was there nobody could do it...but it was the Uchihas responsibility, so for now his responsibility to care for them. He also left a sealed message that only the recipient could read or answer with the lawyer to give to them.
Other than that, Sasuke read and copied a lot. From Foreign to newly identified jutsu to medical ninjutsu to whole history books to things he just found interesting to Itachis academy text books.
It took a bit of time until finally, on the last weekend of the second month since Sasukes world was destroyed and he had to try to figure out a way to adjust or piece it back together, Sasuke stood again in his fathers lab, artifact in hand.
He painted the seal on his shoulder with the help of a mirror, using his blood as the seal-ink.
He used more of his own blood to paint the seal that might take him back in time, bandaged his wound and took a deep breath.
He was fully packed. He had an obscene amount of weapons including explosive tags, combat pants, a mesh shirt and a long shirt with long arms jn black without the uchiwa on it from his cousin, a coat full of steel rods equipped with seals that made it light and pockets from one of his aunts that had once purchased it in Uzushino- the Practical thing about the coat was hat the pockets were storage seals and the temperature was adjustable- that was kind of way to big on him but that particular aunt was always on the small side so sasuke didn't drown in it but it civered him till the knees. That didn't bother Sasuke-the coat was too practical and lightweight not ro wear it and Sasuke had more than enough space to maneuver inside the coat, lots of food and medical supplies and a fee personal keepsakes like a family photo as well as the newest medical textbook that was once published by senju tsunade and a book the uchiha doctor kept on Uchiha illnesses things and treatments.
Then Sasuke closed his eyes, did the calming genjutsu on himself and slowly pulled up chakra from the artifact into his seal. When there was no chakra anymore there and the chakra was with him he felt weird.
For the first time in forever Sasuke didn't feel alone anymore, he felt warm.
Sasuke gave a small laugh. Maybe that made everything worth it even if it might fail now? His intentions and the moment of not-being-alone?
He sighed. It wouldn't do to think too much no, lest he get cold feet. He had a duty to do.
And so, Sasuke activated the seal with a mix of his own and the artifact chakra.
And he disappeared from this place of existence.