I don't understand why orochimaru gone so far to get new body, research, taking alot life, etc in order to get young and powerful. Why don't just learn byagakou seal from tsunade? Can looked young, can heal yet powerful.
He cannot use the byakugou seal. In fact, when Sakura used it, Kishi made her point out the fact that she does not need to regenerate her youth. While it seems that Sakura was looking strong, it is actually a limitation to her use of the seal.
In case you forgot, every human cell as a limited number of replication. Thus, Shizune thought that Tsuande should not use the seal to regenerate. However, she discounted the fact that Tsunade is Senju and Uzumaki. Thus, Tusnade can regenerate (replicate) her cell at a rate higher than normal human being.
If Sakura should do the same, she would reduce her life span big time because she is neither Senju, nor Uzumaki. This is the same for whatever body Orochimaru would take as long as that body is neither Senju nor Uzumaki.
This is why Orochimaru had to experiment from one body to another. But now that he has Hashi-like body, I wonder what he would do next.
