This... this is a whole different kind of psychic damage here. When nightmares got Marcille, we get to knew that her's biggest fear is outliving her friends. This isn't even canon probably, but look at this. This isn't a "I don't want my friends to die" kind of dream. This is a "I'm terrified of loosing my daughters, of something killing them, and being incapable of stopping it" kind of dream. It's so simple yet it explains perfectly the whole of chilchucks character. He loves, he cares, deeply. But he, or doesn't acknowledges, or doesn't know what to do with that knowledge.
Besides that. Someone had to wake him up after this. Imagine the devastation in this man after he wakes up. He just saw his three little babys murdered corpses (or maybe he saw them die, wich isn't better). He would possibly not talk about it, and that would worry the hell out of the party, because we'll, they see him all down and only one of them knows what he saw. Imagine being the one to pull him from that nightmare. Seeing this man, usually so composed, fuking staring with tears and terror in his eyes to the composes of what you can only assume are his daughters. It would be heartwrenching.
Idk, I love this man so much...