"One Punch Man meets Harry Potter". You've got an indifferent OP protagonist (similar to Saitama or Mob) and a premise like Black Clover where the protagonist has no magic at all, but trains hard and uses brute muscle strength to outdo powerful magic. It is obvious that the author takes a lot of inspiration from Harry Potter, but a lot of the art and humor seems heavily inspired by ONE, and just like One Punch Man, it blurs the lines of being a gag manga and being a serious fantasy shounen. If you're a big fan of OPM or Mob Psycho, I think you'll absolutely love Mashle.