User blog comment:EmpyreanSmoke/Supernatural Q&A/@comment-73.212.71.148-20150920175029/@comment-24834479-20150920203131

1. Perhaps the blast from the God Weapon blew it out of him.

2. I think that might have been a mistake on the writers part. She was most likely put into a coma by the witches spell.

3. If the mark hadn't corrupted him, he would have.

4. It was not designed for Michael, so yes, I think that God is saddened that both of his sons are imprisoned.

5, He was in the middle of a war against Lucifer.