Mega Drain inflicts damage, and up to 50% of the damage dealt to the target is restored to the user as HP. If this attack deals 1 HP of damage, 1 HP will be restored to the user.
If HP is restored to the user when its current HP is greater than its maximum HP, its current HP will be set equal to its maximum HP. If used on a Pokemon with the Liquid Ooze Ability, the user will lose the amount of HP it would have gained instead.
A nutrient-draining attack. The user's HP is restored by half the damage taken by the target.