Psywave causes a random amount of damage. Minimum damage is 1 point;
maximum damage is 1.5 points per level of the attacking Pokémon.
This averages out to roughly 75% of the attacker's Level per
hit. However, when you factor in the Accuracy, it brings the Average
Damage down to about 60% of the attacker's Level per use.
The opponent's use of defensive attacks such as Light Screen, Harden, and the defensive aspect of Amnesia, and/or offensive attacks such as Leer or the Special-lowering side effect of Psychic have absolutely no effect on
the damage caused by this attack.