(When Dean refused, Adam became Michaels vessel for the brother-on-brother showdown with Sam/Lucifer.)
But if theres one thingSupernaturalhasnt been shying away from in its15th and final season, its familiar faces.
EW chats with Abel about his return below.

Credit: The CW
ENTERTAINMENT WEEKLY: How did this come about?
And I was like, Me too!
Im okay with those bookends.
I think thats kind of cool.
After all that build-up, was Adams return what you expected?
Was it spectacular?I dont think its over.
I think its leading to something spectacular, or at least I hope so.
I was like, I dont know, Im just here right now enjoying this.
What Adam and Michael are doing in this episode is setting up all the stuff thats about to happen.
So thats my hope.
But for now it definitely feels like a setup.
Co-showrunner Andrew Dabb has mentionedMichaels return, and we saw two of you inthe trailer.
Thats been the big question.
Thats what everybody wants to know!
I speculated, which is the fun part, so I want people to keep speculating and be surprised.
So it sets up some surprises, and expectations might be upset in a good way.
I ultimately didnt because I relied on everybody else as far as what happened up until now.
What do I know?
What dont I know?
Luckily I didnt do any crazy accent or anything, so that helps.
[Laughs] Its a funny thing when you put on the outfit.
I was like, Why do you guys make me feel like a kid?
What was the experience of returning to set like?
Did it feel like the same place?One hundred percent the same.
So going back there was like being back with people that I knew.
I didnt feel that way on this set.
It was two weeks of play and having fun with old friends.
Supernaturalairs Thursdays at 8 p.m.
ET on the CW.