Enchantment, 3R (4) Whenever a creature comes into play, that creature's controller may have it deal damage equal to its power to target creature or player of his or her choice. "If we cannot live proudly, we die so!" —Eladamri, Lord of Leaves
Illus. Pete Venters
The triggered ability (see Rule 404) is played and controlled by the player who controls this card, but the controller of the creature at the time the creature came into play makes the choices. [Time Spiral FAQ 2006/08/30]
The triggered ability (see Rule 404) does not check the creature's power until the ability resolves. If the creature is not in play when the ability resolves, it does damage equal to the power of the creature right before it left play. [D'Angelo 1999/06/01] This means that if a creature comes into play which can destroy itself as a "comes into play" ability, the order of resolution of the triggered abilities does not matter. [D'Angelo 1999/06/01]