Sasuke Uchiha but it might change if what I hear is true that he wants to be...
possible spoiler
hokage. If it is true then it would be Minato bad if he goes tailed beast mode too then It will be Orochimaru. I hope they do not ruin him in some way. Edit: It is true so Sasuke before that happens is my পছন্দ but if আপনি don't accept that answer then it is Orochimaru.