Faith Unbroken

Two effects that white had long sold separately, bundled at a single rate: removal that exiles, and an aura that pumps. The trick is that the same card that strips your opponent's best creature also makes one of yours bigger, so the tempo swing runs in both directions at once. That doubling is also the liability. Because the exile lasts only as long as the aura stays put, any answer to the enchantment is an answer to two cards at once: kill or bounce the creature wearing Faith Unbroken and the +2/+2 evaporates while the imprisoned attacker walks free. White has a long line of these conditional jailers, from Journey to Nowhere to Banishing Light, but those exile and ask nothing further; this one ties the prisoner's release to a body you have to keep alive. It rewards putting the aura on something already hard to remove and punishes spending it on a fragile target, since the two-for-one you built can collapse into a two-for-one against you. The design is a study in how white likes to price its catch-all answers: never quite unconditional, always with a thread an opponent can pull.