I feel kinda bad for the other kids, honestly. Usually this trope has the MC showing off to a bunch of high class people or something whose egos might need to get taken down a peg, but instead it's just poor commoner kids he mistakenly walked in to test with. And inevitably, some of them who might be thinking "wow a commoner can be that powerful? That's cool!" will just get reminded that nobles are still better than them when it gets revealed to everyone that Cain's a noble.