Unholy Indenture

The trick here is that the Aura sees its own host through to the other side. Most creature Auras evaporate as state-based effect the instant the enchanted creature dies, leaving you down a card for nothing; this one converts that death into a delayed reanimation trigger that returns the same card under your control, upgraded. That reversal turns a fragile two-for-one liability into a resilience engine and, crucially, a theft spell: stick it on an opponent's creature, then supply the death yourself with an edict, forced sacrifice, or your own removal, and the creature comes back on your side of the table with a counter on it. The design lives on that timing seam. It cares about the card returning to the battlefield rather than staying attached, so the Aura is spent goods once the loop fires; you get one conversion, not a permanent leash. The obvious partner is anything with a strong death trigger or leaves-play value, since you bank that trigger and then reclaim the body. It is a slower, sorcery-speed answer to the old problem black has always poked at (turning an opponent's threat into your own), closer in spirit to the reanimation-as-removal line than to a clean kill spell, and it asks you to already have the death in hand before the Aura earns its cost.