Gut, True Soul Zealot

Attacking is the only trigger, and that constraint tells you exactly what kind of commander this is: not a passive drain engine that whittles a table down over turns, but a red-zone aggressor that demands you swing to extract value. Each attack lets you cash in a spent creature or artifact for a 4/1 Skeleton with menace that arrives already tapped and attacking, so it joins the assault without waiting a turn to matter, though the token is created during the declare attackers step, which means opponents still get priority to respond and can throw two blockers at it before damage. The input flexibility opens the deckbuilding: Blood tokens, Clues, Treasures, expendable mana dorks, anything an aristocrat shell was going to spend anyway feeds cleanly into a fresh attacker, and that attacker becomes next turn's fodder, so the engine metabolizes its own output. The Skeleton's stat line is a pure glass cannon: four power where a race wants it, one toughness because the token is built to connect once rather than survive a block, with menace taxing the defender into a double-block on a body you were already happy to lose. As a legendary Goblin Shaman with a Background slot, it drops into the partner-style command zone as the aggressive half of a two-commander plan, leaning on a chosen Background to supply the recursion or card draw the sacrifice loop otherwise starves for. It sits precisely where go-wide tokens meet sacrifice value, and the requirement to attack is the leash that keeps it a threat you pilot forward rather than a machine that grinds in the background.