I think I figured out why my new cat has been attacking my other cats. I brought him to the vet and they told me he has a tooth so broken, the nerve is exposes. The vet said the cat is probably in a ton of pain and might be lashing out. It makes sense because the cat is otherwise calm and cuddly and seems to want to play with the other cats until he doesn't. Is the tooth really that much of a trigger? I want to help him integrate to our house but dental surgery is also very expensive. Thanks!