Mostly because I'm an exorcist and I just won't die. [He laughs lightly, but then he gets just a little serious.] We're on opposite ends of a Holy war. The Church and the exorcists use Innocence to fight in order to destroy akuma and save humanity. The Earl and Noah control the akuma in order to destroy humanity. Obviously, there is some conflict between Noah and exorcists. But I cannot forgive the Earl or the Noah for the death and suffering of so many. I cannot allow people who want to destroy mankind win.

[Headquarters...his first true 'home', the home of his friends, was destroyed. Finders, scientists he knew...Tapp...all killed mercilessly.]