Fools and madmen

Revenge is a poison. Revenge is for fools and for madmen.

That's what he told a victim's daughter once. And it's not total nonsense, like he pretended to believe when Lisbon asked him about it.

He knows that his need for revenge is much more dangerous than any cup of belladonna tea.

However, he doesn't care for sanity. He doesn't care for his life either.

Since his family was murdered, he's nothing more than a walking dead.

All that matters to him is accomplishing his task.

Death or insanity will be nothing short of a merciful deliverance after that point.