Let's share some theories about Kabutoro (Kabuto + Orochimaru) here. My speculations below are based on the current opening, so don't read if you consider it spoiler:







I generally don't pay attention to details in openings, but after watching this a few times there's one thing that's hard to miss. In the beginning, after the characters are shown, it looks like someone is taking a Sharingan user's eye. You get a flash of a face that reminds of Orochimaru, and in the next scene Sasuke is fighting with an eye shut and you see a bleeding Mangekyo Sharingan eye.

My conclusion from this is that Kabutoro somehow steals one of Sasuke's eyes. (Orochimaru finally gets the Sharingan, yay). If that's the case, he would probably become a main villain again. Maybe he wants the power of a tailed beast next (did Orochimaru ever show a interest in those?).

What kind of role do you think Kabutoro will play in the future?