Ulamog, the Infinite Gyre

The cast trigger is the genuinely radical part, and it's what the Eldrazi titans introduced to the game: a destroy-target-permanent effect that resolves before the creature ever hits the battlefield, on the stack, where no counterspell aimed at the body can save you from the removal. You pay eleven, and once that cast trigger resolves you have already destroyed something; the 10/10 indestructible creature is almost a separate transaction. Annihilator 4 then turns every attack into a sacrifice tax that outpaces normal blocking math: the defender loses four permanents whether or not they have a chump, so even a perfect block bleeds them dry. And milling it backfires, because Ulamog hitting the graveyard reshuffles it back into the library; mill cannot deck you out, and graveyard hate often just rebuilds your deck. The titan resists interaction from three directions at once, which is precisely what makes it a finisher worth the colorless ramp era's setup. What balances it is the only thing that can: the eleven generic mana, a cost so steep it defines an entire archetype of acceleration and big-mana lands rather than slotting into existing decks. This is the closer that demands you assemble the whole machine first, and rewards you with a permanent that punishes removal, blocking, and graveyard hate in a single resolution.