Jack is a monster.
He was possibly sent to Earth when he was a baby for unknown purposes/reasons and was transformed into a human by magic.- Explains why Rezzoch is able and wants to possess him.
Quint has Autism.
He is a genius inventor. Jack said that he sees things different than him and Dirk. He is also shown to get angry at his friends and enemies. Thrull used to be a hero.
He took down a Dozer which is a monster of Rezzoch, and said he hunted other servants.- Confirmed in the books, where he slayed a species of Blarg.
Someone else opened the portals to the humans' dimension.
- Implied in the books, where it is suggested by Bardle.
