Imagine what it would look like, I found a reason to like Sasuke.
It was a skill that Sasuke was going to use then orchimaru stopped him. We still don't know what it is till this day.
Kakashi can't use rasengan. It's the old eremit with the white hair, one of the 4 sannin his name is ..... Rasengan isn't a move which can be done by seals and to make this move you have to do a difficult chakra control.
Does someone has the atk of Itachi in his mind where he encounters the eremit it was black fire. Probably sasuke does a blacklighthning
Even though he was a tailed beast...the old guy Kisame and Itachi fought had alot of affinities...it was just that he was old and outnumbered why he lost. Go back and read if you guys dont remember.