[Kanji_The_Wanderer]

I know Kira does his own will. He says he IS "GOD" lol so yeah, as the story goes on, he gets worse and worse.

Yeah, in my opinion, I like L and Kira equally. They are both so awesome, and look really cool. DN is the first manga/anime {that I know of} that portrays a character who is starting to turn evil as the main role.