Here’s a broken combo: play Soul Foundry, imprinting Zedruu the Greathearted. Make a Zedruu, and use its ability to give it to one of your friends. Then clone it, and use the clone’s ability to donate itself to another one of your frenemies. Now use Clock of Omens to untap Soul Foundry and make another Zedruu, which you can then donate to another player. Repeat until everyone has a Zedruu, and then make one for yourself. Draw/lifegain engine, baby!
Do the combo above, only with Carnival of Souls in play to get a lot of mana and/or die. Carnival of Souls is a One Card Combo™ and should be banned immediately.
Play Brothers Yamakazi. Play another Brothers Yamakazi. The legend rule doesn’t apply to them! HA! Brothers Yamakazi gives no shits about your stupid rules changes! (Of course, you’re playing an illegal deck, but who cares about that either!)