Marc: Probably either Ravenclaw or Hufflepuff
Dorian: Hard-core Hufflepuff, he has a task he's been working on for centuries, out of loyalty to his people.
Pela: Slytherin. Not so ambition but cunning and resourceful? Oh yeah.
Adel: Probably end up in Gryffindor, because he couldn't imagine anything else. Bit of a competent Ron Weasley kind of Gryffindor.