Bloodthirsty Ogre

The first ability banks a counter; the second converts the accumulated total into a -X/-X shrink without spending any of it, so each charge stays on the Ogre and every subsequent activation hits harder. The math is patient by design: the turn you start charging does nothing, but a stack of four or five counters turns this into repeatable, scaling removal that erases something new each turn. What gates the whole apparatus is the Demon clause. The minus-toughness ability simply will not fire unless you control a Demon, which makes this a payoff inside a deck already committed to its biggest, ugliest black fatties rather than a standalone toolbox piece. That condition is the price for an effect that, left unchecked, would grind a board to dust one creature per turn. It also makes the 3/1 frame almost beside the point: a body that wants to tap every turn instead of attacking is a control valve, not a beater. The design rewards a black deck that already has reason to keep a Demon on the table and the patience to charge a battery across several turns before pulling the trigger. That is a narrower ask than the raw rate suggests, since the counters only matter once the gate is open, but a deeply satisfying one when the pieces align: a recurring removal engine that scales with how long you have been allowed to live.