Adrian destroyed the asteroid using a powerful kinetic pulse as he was firmly imprinted on it. He already predicted that he would be at the losing end of the clash but did so anyways. This was an evaluation on how far his understanding of Force Magic is. He is not here to be victorious but to show everything that he has understood about Force Magic.
In fact, if there was an element that he has yet to fully understand in the magic system of Origin Magic then that would be force magic. He is not using this magic system much as he does not have the perfect body for it, but it does not mean he cannot use it. The perfect body for Force Magic is a body that can exert maximum force through muscles like the Diabolon.
"I think I broke every bone in my body." Adrian commented.
"I do not doubt that. Hitting that force of destruction is the same as running into a mountain." Elder Ascalor stated as he heard what Adrian said.