Oh I get Roland. He and Circe have every reason to know an Imp's capabilities from all their studying. That's fine. It's just the error of Ceiran that amuses me. Unless that was an intentional attempt to misdirect people from thinking he has any knowledge or intuition into demonology.
 
And since Circe and Roland are well acquainted with such monsters from their studies, I'll drop a little bio they should know.

Imps: Lesser demons. Possess the strength of your average human. Capable of limited flight. Possess powers of illusion and deception, complimenting their trickster nature. The pranks they pull are usually more dangerous then they are by themselves, and are prone to fleeing once the situation turns against them.