The Merchant Guild has its own, old style mecha, armor is plating, instead of being directly integrated into the mecha, which means no pain feedback on the armored bits. And they're perfectly happy with him acting as a sniper, since they don't want to spend time and money making repairs just because melee combat is more "knight-like". It and its magic wand (basically a rifle) actually have higher tolerances for magic power as well, I think C rank magic is pretty manageable? Can't remember if it's C or B rank that produces a super huge destruction beam that destroys man, mecha, and monster alike. Basically, instead of using the magic to create a potion or cast healing, he uses that collected magic power to move the mecha or fire its rifle. Despite him only having a set number of uses a day, since the power isn't immediately used up, I can't remember an instance in which he runs out of power for operating the mecha or its gun.