Tectonic Fiend

Two clauses, pulling in opposite directions, and the friction between them is the whole story. Echo asks for the full a second time on the upkeep after the creature lands: a one-time toll, not a recurring one, but a steep one, since paying it means committing twelve mana across two turns to hold a 7/7 you have not even swung with yet. Decline the toll and the body is sacrificed on that upkeep, before combat ever arrives, so the skip-the-echo line never buys you an attack at all: you simply spent six mana to watch the creature crumble. Pay it, and the forced-attack clause takes over. From then on the Fiend marches into combat every turn it is able, with no haste to let it swing the turn it enters and no discretion to let you hold it back once it can. You pay a premium to keep a creature you then cannot deploy on your own terms, walking it into ambush blocks and profitable trades the opponent dictates. This is the old red bargain rendered as a single card: enormous, cheap-to-deploy power handed over with a will of its own attached, in the lineage of red beaters that swap your decision-making for raw stats. The echo is the entry fee; the attack restriction is the lease term. Neither is negotiable, and together they make a 7/7 read smaller than its numbers.