Expel

In Commander, Expel earns its slot in white decks that can reliably tap creatures before they untap — combat-heavy metas make the restriction largely irrelevant, and exile over destruction matters against recursive threats like Mikaeus, the Unhallowed targets or Atraxa, Praetors' Voice. In Pauper, it competes in a tight removal market and the tapped clause is a real cost against aggressive untap synergies, but the exile clause makes it distinctly better than Pacifism effects in that format. In Modern and Legacy, Expel is too conditional to see serious play — two mana at sorcery-equivalent timing can't compete with Path to Exile or Prismatic Ending. Oathbreaker mirrors the Commander read: useful, unpretentious role-player.