Hour of Need

Commander is where Hour of Need does its best work — the format's creature-heavy tables mean you'll rarely lack targets on either side of the battlefield, and instant-speed token generation at the end of an opponent's turn is exactly the kind of play the format rewards. The Sphinx tokens are big enough to matter on a board that's gone wide, and the spell's scalability means it converts excess mana into board presence without dead-drawing at low counts. In Legacy and Vintage the card is legal but irrelevant; those formats move faster than a four-mana token spell can keep up. Modern and Pioneer have enough efficient threats and interaction that Hour of Need never finds a competitive home there either. Oathbreaker shares enough of Commander's multiplayer texture that the card can slot in blue token or tempo builds to similar effect.