Lullmage's Familiar

Commander is where Lullmage's Familiar does its best work — multiplayer tables make the hand-size disparity easier to maintain, and the upkeep refill compounds draw-heavy strategies over a long game. In Modern and Legacy, a 2/3 for three mana with a conditional tax isn't competing for slots in decks that have faster, more reliable disruptive options. Pioneer offers slightly more room but still lacks a shell that wants this effect badly enough to run a three-mana creature for it. Oathbreaker mirrors Commander's appeal at a smaller scale — if your planeswalker generates card advantage, the Familiar's tax can become a real obstacle for opponents.