Blightsteel Colossus

Infect on a body this size is the whole math problem: ten poison counters ends a game, and an 11/11 with trample carrying infect deals eleven in a single connection. That overshoots the kill by one, which tells you the design was never about a combat curve at all. The shuffle clause is the giveaway. A creature that refuses to die and refuses to stay in any graveyard is built for one purpose: to arrive onto the battlefield by some means other than its own mana cost, swing once, and win before it can be answered. The indestructibility and the anti-graveyard insurance exist to protect a combo, not to make a fair finisher durable. Tinker, Polymorph and Tooth and Nail, the various free-put-into-play tricks: the colossus is the payoff that justifies all of them. The replacement effect is the precise design discipline here, because it shuts the back door entirely. Since the card can never reach a graveyard, every reanimation plan is dead on arrival, and so is any deck hoping to discard it cheaply and bring it back; the practical route is to put it directly onto the battlefield from hand or library. The cost is deliberately absurd because no deck is meant to pay it; the printed twelve is a wall the card dares you to vault rather than climb. Strip away the flavor of the Phyrexian apex predator and what remains is a single-card kill condition engineered to permit one category of cheat and forbid the other.