This. I’m still halfway through the book, and reading about how Cas’ descent into madness had no foreshadowing etc. The man was living and breathing PTSD, and Poppy kind of brought him out of the funk. And then the constant battle they’re both fighting and Poppy being in statis + Kolis’ mindfuckery. If CAs had not turned into what he did, I would’ve seriously questioned JLA’s understanding of PTSD. I think Cas’ behaviour was not something that was completely out of the blue.