At the beginning of your upkeep, you may put a treasure counter on Legacy's Allure.
Sacrifice Legacy's Allure: Gain control of target creature with power less than or equal to the number of treasure counters on Legacy's Allure. (This effect lasts indefinitely.)
10/4/2004 The “power less than or equal to the number of treasure counters on this card” restriction is a targeting restriction and will be checked on resolution in addition to on announcement. If the creature’s power changes to be greater than this before the effect resolves, then the Legacy’s Allure triggered ability doesn’t resolve, but the card stays in the graveyard.