Elspeth's Smite

In Commander, Elspeth's Smite is a role-player in white aggro and token-matters decks where you're already in combat frequently enough to trigger it reliably — outside of combat it does nothing, which limits its flexibility in a four-player game. In competitive 1v1 formats like Modern and Pioneer, the combat restriction is less punishing because threats are attacking every turn, and the exile clause cleanly answers Persist creatures and token generators that would otherwise recur. Legacy and Vintage don't want it; the threats there die to cheaper, unconditional answers. Standard is the friendliest home, where the one-mana cost and exile rider outperform most common removal at the same price point.