Shawn's mask can be used to give him a robotic exoskeleton. It adapts, so he could make a weapon of choice be created on his arm. It could also protect him as a safety bubble. He calls it "Hidden Fury".
Upon entering the world of Remnant, he gained a strange semblance that allows him to grow 6x his original size when he gets really angry. This, obviously, helps the team out greatly when shows of extreme strength are needed. And Hidden Fury, his mask/weapon can even adapt to that and make him even MORE powerful!