Realm Razer

Armageddon with a hostage clause stapled to a fragile body. The first trigger wipes every land off the battlefield, yours included, which is the same scorched-earth move the symmetric land destruction spells of old made: blow up the manabase from a position of advantage and ride your tempo lead to the finish. The wrinkle is that the lands aren't destroyed, only exiled, and they come home tapped the moment this creature leaves play. That turns a permanent reset into a temporary lockout. Everyone is shut out of their lands for exactly as long as a 4/2 stays alive, and a 4/2 does not stay alive long: it dies to almost any burn, any blocker, any removal an opponent can muster while drawing from an empty mana pool. The design tension is the whole point. You get the devastating effect of mass land exile only by committing it to a body the format is built to kill, and the instant it dies the lands snap back tapped, so even the player who answers it eats a turn of catching up. It rewards the kind of plan that has already emptied its hand onto the board and can close before the lands return, the same way the classic land-denial decks wanted their threats deployed ahead of the wipe. Give it protection or a way to cash it in on your own terms and the lock tightens; left to fend for itself, it is a clock you start and someone else stops.