My Angel My Demon [Completed]

Angelic or Domonic? Maybe both, a mixture of the two; a powerful being who has been searching for his everything. That one person who makes him all he is meant to be. His past troubled and future unsure what happens when he finds her? Selest is alone and fearing it will always be that way, she hates it... Nothing makes her complete, she has her dog but that is little compensation for another human. So when she stumbles upon a man, no not a man! No man ever looked like him, she does not know what to do. Run! Stay, help him? Something about him made her want to help him, she knows nothing about him but then she knows everything. Could this strangers past really behind him or will it follow him to his future and threaten everything that makes him who he is?
Credit of this summary goes to littledevil93!