He felt that it was going to be over when he had that chidori. So he deactivated his sharingan because he thought he already won and that's why he lost. If he would've kept his head in the game he Naruto would be dead...but he didn't
Also does anyone think he just doesn't have a left arm now? Naruto has bijuu and can regenerate that way but sasuke doesn't. Only solution i can think of is orochimaru somehow giving him a new one
Also does anyone think he just doesn't have a left arm now? Naruto has bijuu and can regenerate that way but sasuke doesn't. Only solution i can think of is orochimaru somehow giving him a new one