Thoon is a “self-centered” champion. This is a champion that can win the game by himself but needs a lot of support. The key to making Thoon a star is to bring him into play, and use Blood Shamans to instantly give him lots of boosts, so that you can keep a 7 strength ranged attack. If you have that support and the magic, then summoning Thoon can be game winning. But if you don’t have the Shaman + boost to spare at the moment Thoon is in your hand, then you should probably pass on him.