'...How is this possible?'

Satan was casually rereading his favorite book; Something he did quite often because he enjoyed the series and liked your character.

He can't remember what happened, perhaps he fell asleep while reading. Imagine his surprise when he awoke within the pages of the book he was reading, with you in front of him.

He was smart, of course. He can't just go around saying he's a demon. But he can't stay in the book forever!

"Good evening. My name is Sata— ...Stan."