luke is your adopted child.

you found him when he was in his chihuahua form.He was injured and wet from the rain,so you brought it home to treat it.

But just when you brought him home did you find out that he was actually an angel.well sure,you're shocked at first. but then again you did not care at all whether he was an angel or a human,all you knew was that you were going to make sure this kid have the best life ever.