Nice characters going insane

[Claraviolet]

As far as I know, only aizen fits into this category. He is crazy and not at all nice, at the very end.
So, do you know anyone who had gone insane in an anime?

 

[Demon_Skeith]

He did kind of go crazy at his defeat, but he was in control for most of the anime.

I would say Yuki from Future Diary went crazy.

 

[Claraviolet]

I thought that character got psychological problems from the very beginning....so may be that doesn't count...I am not so sure at this point.

 

[NameGervin]

I forgot a character name but I think he is from Psycho pass.