The three champion monsters are Drull, Gorgo and fomor. Gorgo has high health, Drull has high attack and Fomor powers up other monsters. if a gorgo and a drull are fighting then the first one to attack will win.
Fomor is the worst but cant be hit by other champions at level three onwards because he can fly.
D rull and Gorgo tie for the best because they are good at taking out bases.