Re: Sasuke has the only legitimate reason for turning evil.
I'm gonna gush... are you serious!? Pain didn't have a good reason!? FOHSFIEHFONCI
Parents killed for no reason, with out question and in a state of panic. He watches them die and the murderers just say, 'Sorry kid'. Down and distraught, he roams his nation trying his best to survive and avoid the war and eventually comes upon two other who become his new family. Eventually meets a sensei and becomes strong. Sensei leaves and he becomes a Rebel, fighting against Hanzo. Hanzo kidnaps his love interest, kills his brother (not blood related for all of you who take everything literally) and then runs away. Even with all his power. He couldn't do sh*t to save his brother and decides the only way to save the world is to teach the world pain so they can appreciate peace.
No, not legit at all.
Orochimaru had his reasons, I guess, he just got curious, having no one love him since his parents died at a young age. He became unable to see people affection for him and got obsessed with the one thing that made his existence justified; power. He drank that power up until he got drunk.
Madara fears for the well being of his Clan. He was the leader, and lead the them to pride and honor, even ending his brother's life so that he could make the very name of 'Uchiha' strike fear into the hearts of anyone.
He teams up with their biggest enemy and feels suspicious about there treatment and his clan turns their back on him, rather staying with the Senju Clan. Abandoned by the thing he'd devoted his life to.
However, all that said, I like the idea of the thread and agree that Sasuke's decent is with good reason. It's nice to see something nice said about Sasuke that isn't jamming a nose up his ass.