Honestly this is the worst idea i have had the pleasure of having. Considering it would be horribly OP cause of the meta cards currently in master duel. I've had the idea of locking the extra deck to fusion only with the banlist of legend anthology. Or let him have to draw cards from the shop and make cards uncraftable (gets like 3 free cards of the same name)(my option would be time rendering morganite(draw 2 instead of 1 each turn and can normal summon 2x per turn, cant activate effects in hand))
I like yugioh GX fanfics, but there aren't any with newer cards. Probably because they get boring after a while. You really need to use new decks constantly to grasp the attention of readers (like hell I would know, i haven't written shit)
Anyways happy splatfest to anyone who plays splatoon 3 and may mint chip win.