Some spoilers, but mostly theory. I don't know why but I feel like this is going to be a bad ending. There was a scene at the beginning of the game where Cameron was supposedly dying. I won't be surprised if it suddenly turns out that Brian survived and kills one of the main characters or both. There's also the possibility that Duke will do something we don't expect, or some echo beings will do something to us. Maybe it'll be Brian's ghost or something. There's also the possibility that Cameron will only feel like he's dying but he'll live or maybe become a ghost or something. In this universe, life after death is probably sad and full of suffering and existence in some connection with the material world. Maybe it doesn't apply to all souls, I don't know. Maybe it's not even a kind of soul, but free consciousness without a body (in theory, still a soul). It would also be interesting if there is a reference to the scene where Cameron sees his boyfriend hanged, but this time for real. These are my theories only but something feels that the ending will not be happy or not fully happy. The most likely for me is that Brian is still alive and will kill Cameron who will become one of the ghosts in Echo. I think Devon and this feline friend will survive.