Hi guys. In the new promos I noticed a few things that lead me to the conclusion that Lucifer will possess Castiel/Jimmy.
- Dean said "We're gunna save Cas, we're gunna ice the devil, and we're gunna shank the darkness". This means Cas will need saving and Lucifer will be free.
- Castiel was all feeling up Rowena in the promo.
Remember who Rowena was crushing on in the last episode? Lucifer.
- This photo
shows Sam and Dean looking at a blinding white light in the cage.
I think this is enough to say that Lucifer will use Castiel as a host...