What happens When an angel of the lord falls for the quiet and reserved Slytherin witch with the abusive Mother? Why, Its magic darling!!

The angels have fallen. Castiel lost his grace, and is now a human. He experiences hunger, cold, need, but still pondered at the thought of love. Dean takes him under his wing and helps him understand his new way of life; every aspect. Even though his grace is lost, the affair between a man and an angel is forbidden. Not to mention, an angel and a Winchester. In addition to the internal conflicts between the two, they also have to worry about the bounty put on Castiel's head by the other fallen angels.