I don't think think that Hamlet is evil ,even after seeing his actions. By having to bare the grief of how his father was murdered by his own brother and Hamlet's Uncle, was a major loss of innoncence. Also not to mention the fact that his mother remarried 2 months later to the very same man. His whole world was turned upside down. I think it was possible he lost some sanity. Think about it, there was no right or wrong anymore. Everyone that he was around all betrayed him. Even Ophelia who was just a pawn. Hamlet didn't care anymore.