[@vancexentan] That explanation is
great and all but

If they know all this stuff then kindly remove yourself from the academy? I don't want know-it-all students that are better than the rest. I don't like being rude here but feel like I have to. It's not fun. 

Plus, the excuse you gave is bad. Yuma had been dueling since pretty much a toddler and, agreed he was an idiot, but never really learned how to duel proper until someone basically told him 'ALRIGHT, GET THE HELL UP WE'RE DOING IT RIGHT THIS TIME'. In the same vein, Yuya's dad is a professional but Yuya himself is a pretty average duelist that didn't really know how to use the extra deck methods. And even if the combo got used once, I don't think a true character in the YGOverse would really begrudge the deck or even remember it all that much.

Like, this all seems EXTREMELY OOC for a setting like this. I don't want characters to know everything right off the bat, [i]it's not fun[/i].