Hixus, Prison Warden

The trap hinges on a single word in the trigger: it fires only on a creature that deals combat damage to you. That word does all the structural work. This is not a blocker that exiles what it eats; anything it blocks that fails to connect with your life total never trips the trigger. The captures come from the swings you let through: holding up five mana, flashing in the 4/4 after blockers are declared, and allowing the unblocked attackers to land their hits so the trigger snaps shut behind them. The "entered this turn" clause keeps this from being a standing prison. The trap stays armed for any combat damage you take on the turn Hixus arrives, then goes dormant once the turn ends, so it is a one-shot ambush rather than a lockdown you can park on the battlefield: cast it early and every extra combat step that turn still feeds the cell. The exile is conditional on Hixus staying alive, which puts the whole tension on a four-toughness body: the opponent's path to reclaiming their creatures runs entirely through killing the warden, and every prisoner walks free the instant he dies. That makes Hixus a removal magnet by construction, an answer that doubles as a target the moment it resolves. The shape reads as white's response to the alpha strike, punishing an over-commitment to combat that an open mana count should have warned against, and the flavor of a warden closing the cell on the prisoner who walked in tracks the rules precisely.