Umbris, Fear Manifest
Exile is usually a one-way door: a card gets shoved out of the game and forgotten, which is precisely what makes it feel permanent. This inverts that. Every card an opponent owns in exile grows the body, so the pile that normally represents cards that stopped mattering becomes a running scoreboard for how big the threat gets. The enter-the-battlefield trigger keeps feeding that pile, digging into an opponent's library and exiling cards off the top until it hits a land. Note the mechanism: those cards are exiled, not milled into a graveyard, so they immediately count toward the size. The two halves lock together. The more you strip away, the larger the punisher grows, and because any Nightmare or Horror you control (not this one creature alone) sets off the exile burst on entry, a tribal shell converts every new body into another chunk of removed cards. The growth is untended, too: it counts every card any opponent owns in exile across the whole game, including piles created by outside exile effects, without a counter you have to pay mana to maintain. The land-check is the throttle. Because each trigger stops at the first land it reveals, the engine escalates steadily instead of dumping an entire library in one trigger, which keeps a 1/1 climbing on a curve nobody at the table can slow down.
