Warstorm Surge has a triggered ability that triggers when a creature enters the battlefield under the control of the controller of the Surge. When this trigger goes on the stack a target creature or player is chosen. When this trigger resolves the target will receive damage equal to the power of the creature that entered the battlefield and triggered this ability.

The amount of damage dealt it determined when the ability resolves. In other words, players can raise or lower the power of the appropriate creature in order to raise or lower the amount of damage dealt.

However, removing the creature from play will not prevent damage from being dealt. If the creature that triggered this ability is removed from play before the ability resolves, the game will use last known information to determine how much damage to deal. For example; if a Runeclaw Bear triggered this ability and the Bear is destroyed by a Doom Blade before the trigger resolves, the ability will deal two points of damage to its target.