"Oh. ...Niisama said the 'Junior Youth' competitors were in Middle School... ...but when he sent the 'Youth' competitors to fight, they all lost and turned into cards, so..."

Things may have gotten intense. "When we went to Synchro dimension, he said it was alright for me not to fight though. So...he's not wrong, right?"

Realistically, 'niisama' kind of had his hands tied in most situations. But he did his best.