Mighty Emergence

2008-10-01 The ability checks that creature's power only once: when that creature enters the battlefield. The trigger checks a creature's initial power upon being put on the battlefield, so it will take into account counters that it enters the battlefield with and static abilities that may give it a continuous power boost once it's on the battlefield (such as the one on Glorious Anthem). After the creature is already on the battlefield, boosting its power with a spell (such as Giant Growth), activated ability, or triggered ability won't allow this ability to trigger; it's too late by then. Once the ability triggers, it will resolve no matter what the creature's power may become while the ability is on the stack.

Card is in preconstructed decks:

mtg.wtf