Man, he should just carry around a copy of Makai Kingdom and start it up every time someone asked that question. (Forgetting, of course, that it would show him setting the Sacred Tome on fire, because Zetta had been deliberately omitting that fact for so long now he'd actually started forgetting it himself.)

"Someone tampered with the Sacred Tome. If it gets destroyed, everything gets destroyed with it, because everything that ever is or was is written in it. So I had to bind my soul to the damn book to preserve it."