Board Thread:Naruto Discussions/@comment-26006790-20140725193452/@comment-24519434-20140727093707

The greatest reason for Sasuke to leave was Konoha had no more to offer him in terms of strength, Orochimaru gave him the curse mark and promised more power. He got the Magenkyō after learning his brother who he just killed was really a good man. It's Naruto who's power is emotionally driven (and Gohan, but that's a different manga).