I betting this will backfire at the "Evil Teacher", dunno, it's already clear how experient the MC is, so I don't think he really lose the mock battle.
I may be thinking too much deep, but I'm betting the MC did notice that something wrong with those bloodlust-ish attacks the teacher used and got some hints.
And I'm sure the MC will improve his dark style with the tips the teacher lessoned him.
I want to believe.
😂
Thank you very much for the translation~
😉