I said that Gur was a good guy because he suggested the theory about Breck (meaning he couldn't be a demon), and he didn't vote against me (meaning he's not an angel or a demon). If he were a member of the Mafia (any role), he could easily have supported the others and voted me out; it would have been beneficial for them...
Judging by the fragments, Gur was a poltergeist... but I don't know what the chains were for.