Ib Halfheart, Goblin Tactician

Goblin tribal usually wants its swarm to connect; this commander inverts the incentive by turning a blocked attacker into a damage spell. The trigger fires on the defender's choice, not yours: any other Goblin your opponent blocks gets sacrificed and dumps four damage onto each creature standing in its way, so the act of blocking becomes a trap that trades two-for-one or better against the team. (Ib himself is exempt, since the trigger reads "another Goblin," so the tactician can attack into a block without going to the bin.) That fork is the whole pitch. An opponent who blocks loses creatures to the burst; an opponent who declines to block eats a swarm to the face, and either branch punishes exactly the defensive posture a normal go-wide deck dreads facing. The second ability keeps the board stocked for the bargain, feeding the land base directly into expendable bodies: Mountains become Goblins, Goblins become removal the instant they meet a blocker. The tension is that you are sacrificing your own attackers to make any of it happen, so the deck this asks for treats Goblins as ammunition rather than a board to protect, with a mana base it is willing to eat. A niche engine from an era fond of this kind of left-field combat manipulation, and a curiosity ever since precisely because the effect commits so fully to one strange line of play.