User blog comment:Rafe Adler/"Nightmare Logic" Discussion/@comment-143.202.170.210-20181112122751/@comment-3169324-20181112124229

Castiel would've been able to see him, like the other angel did. It's either because Dean was Michael's vessel for a while, or because Dean's nightmares are so horrible that the Djinn couldn't stand them. Let's not forget, Dean's been to both Hell and Purgatory, having spent 40 years in the former, and 30 of those were under constant torture.