On the first turn, the user dives underwater, becoming uncontrollable, and evades all attacks except for Surf and Whirlpool, which have doubled power; the user may also be hit underwater if it was previously targeted by Lock-On or Mind Reader or if it is attacked by a Pokemon with No Guard. On the second turn, the user attacks.
As long as the user remains in battle, the target cannot switch out unless it is holding Shed Shell or uses Baton Pass or U-Turn. The target will still be trapped if the user switches out by using Baton Pass.
Calculates the average of the user's current HP and the target's HP; the HP of both Pokemon is set to this average. Pokemon can be healed by Pain Split even under the effects of Heal Block.
