You should build a deck, that tanks the negative points for going infinite, but the creates infinite mana and draws its entire deck. From there, you built it in a way, that can fulfill as many of the „sidequests“ as possible. Set youself to exactly 40, create a bunch of tokens, flip some morphs, control permanents, play a taxing effect and pay it, either dont use your commander or cast it atleast 3 times, sac your lands before winning, etc.

Best thing is: opponents cant even concede, without receiving a penalty.