Bloodrock Cyclops

The compulsion is the entire deal: you get a fair-sized red body at a price that asks nothing extra in mana, and in exchange you surrender all control of the combat step. The Cyclops walks into whatever the opponent leaves back, every turn, whether or not the swing serves you. You cannot hold it to block, cannot bluff an ambush, cannot leave it home as a deterrent; once it is down, it commits. That makes it a clean statement of what red trades away (combat flexibility) for what red wants (cheap pressure). The lineage runs back to Juggernaut, which made the same bargain at larger scale, and forward through every must-attack beater since. What the forced swing really measures is whether your deck is built to be the aggressor: on a board you are already pressuring, the compulsion costs nothing, but the moment the game turns and you need the body on defense, it becomes a liability you cannot switch off. The drawback functions less as a tax on the rate than as a referendum on whether you should be running the card at all: in the deck that wants to attack regardless, it is free; in the deck that does not, the clause writes its own punishment turn after turn.