This one was heavy but your writing is still great. It kinda scared me actually... Picturing this stuff is hard but it fits to your story and really impressed me.
In my head Cas has to get better soon... otherwise I won't be able to sleep now. But that's the only good thing about an open ending: you can think whatever you want and whatever lets you go to sleep.
Really very impressing story! Especially how intense you played with soulless!Sam character and Dean's.

Take care,
Kiray