User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-120.28.131.148-20120502112534/@comment-3481504-20120502150503

Two theories on his presence:

1) To eradicate the Leviathans, in way of assisting the Winchesters.

2) To be the possible Season 8's main antagonist. However, how could this be? All he'd need to do is talk, and everyone dies.