User blog comment:General MGD 109/Shōjō?/@comment-4807493-20120405204712/@comment-3481504-20120405222838

No, God ordered it to be done, but it was Michael physically cast him out. Just re-watch "Sympathy For the Devil", it's in there.

Like I said, more modest. He's was subtle is all. But he had the mojo, believe me. Yeah, he didn't really stand a chance against Lucifer, although he did say "without me, you got zero shot at killing Lucifer".

Stayed around during Season 6? Well if that had happened, Cas'/Gabriel's side would've won. With that, he could've killed the Leviathans for the humans.