So you're telling me that Ed is meant to come off as an innocent creature that just had minor bully issues and took it out on a dog and felt regret?
Because he comes off as a fucking twisted psychopath with learning difficulties for me. He doesn't even repent. He's just outright "fuck the dog" at the end. I just thought the dog was a placeholder. More of a "dog" given the carcasses after the context of all the visceral sexual horror we've just seen.