From RocksfallWiki

A mysterious and disturbing stranger who, along with his two terrifying dogs, caused some problems one night in Pearl City. He claimed to be from far away, to have visited the city before, and that he was only passing through on business. He walks with a slight limp and generates a very uncomfortable aura. He later turned out to be a demon who was assisting the thing in the Arch.

Oh yeah, and in case you hadn't noticed, his name is an anagram of 'A Devil". Duh!