Uchiha Shunichi did not return the Nine-Tails' chakra to Naruto's body. Instead, he chose to study it separately with Konoha.
Nine-tails chakra was nothing short of a treasure to ordinary ninja, and it was useful to Uchiha Shunichi as well.
But controlling nine-tails chakra was clearly no easy task, even if it was only artificially cultivated chakra.
The Nine-Tails at full strength had forced Minato Namikaze to sacrifice his life to seal him. If this cultivated nine-tails chakra went berserk, its power would probably come close to that of a real tailed beast, even if it fell short.
After working in the laboratory for several hours, Uchiha Shunichi successfully created a new sealing vessel.
It was another lump of flesh cloned from cells. Although it could not be considered a true living being, the life force it contained allowed it to serve a purpose similar to a jinchūriki.
Of course, more importantly, no one could take this thing away without Uchiha Shunichi's permission.
After all, Uchiha Shunichi had no intention of doing all the work only for someone else to reap the rewards.
"Shunichi, how do you plan to handle this tailed beast chakra?" After Uchiha Shunichi finished his work, Tsunade came to question him before he even had a chance to eat.
"I don't have any particular opinion, but I suggest we stop creating jinchūriki like Sora. This kind of uncontrolled chakra can't make someone a true jinchūriki," Uchiha Shunichi said bluntly.
He did not need this nine-tails chakra at the moment. The only reason he had gone to such lengths to keep it was to use it once he had collected chakra from all nine tailed beasts.
Uchiha Shunichi had no interest in becoming an ordinary jinchūriki, but becoming a Ten-Tails Jinchuriki with complete control did hold