I've already thought of an entire team for Cetus! He has a Vaporeon that's like his main partner pokemon because it's cute and friendly and has his same tail type, but he also has a Primarina, a Gardevoir, a Malamar, a Slowking, and a Lapras. He tends to work with water/psychic type pokemon! Since I kind of imagine that if he was a pokemon himself, that would be his typing.