Shattered Ego

One mana buys a permanent -3/-0, which does honest work on its own: it neutralizes an attacker's damage or blunts a combat-relevant blocker for the rest of the game while you sit on the second half. That second half is the reason to run it. Five mana, once, tucks the enchanted creature third from the top of its owner's library, and the moment that ability resolves, the Aura falls off and heads to the graveyard. This is not a repeatable engine; it is a one-shot answer you keep loaded on the battlefield until you can afford to fire it. What the tuck buys is delay of a very specific kind: the creature reappears as its owner's third draw, so the threat is gone for two full turns of nonthreat cards before it climbs back to the top. Because it goes to the library rather than the graveyard or the hand, it sidesteps reanimation and recursion the same way exile does, without the rules and political friction that exile sometimes carries. The Aura frame is the constraint that pays for the flexibility: you commit the card to a single creature the instant you cast it, and if that creature leaves before you activate, the whole plan evaporates. The cheap static effect exists so the early cast is never dead while you hold up the tuck mana, answering the one problem it was built for: the large, hard-to-kill threat a graveyard deck wants back.