‘Let’s go take a howl at that moon.’
Crowley’s monologue over Dean’s corpse in the season 9 finale was surprisingly earnest. He helped Dean take on the Mark of Cain and continued to shape him as the Mark increasingly affected the older Winchester. But he seemed regretful of Dean’s death, saying that he’d never lied to Dean — only refrained from mentioning that when Cain tried to kill himself, the Mark wouldn’t let him go. We’ll be interested to see what kind of interactions Crowley and demon Dean have in season 10.