This is a holiday to celebrate things people find scary, so I thought it would be fun to come and scare people by having my head off... but Yohane-ya made me put it back on.
[It was more he put it back on because turns out scaring little girls isn't nearly as fun as scaring armed adult soldiers, but she probably would have protested if he'd tried to remove it again anyway.]

You have to remember I'm not nearly as... magnanimous as you.
[He's bitter and jaded and is plenty happy to drag other people down to his level. It just doesn't work on people like you.]