Deathblow

Deathblow [minor] by Iczer

'Well well well. it seems we have to rethink your name 'mr immortal

The character can leave targets with debilitating wounds that refuse to heal.
If the character strikes a target with an innate superpower or an unarmed attack, the target must make a saving throw (14+ PE bonuses apply). If he fails the saving throw, the target's innate healing factors shut down.
All forms of regeneration ceases for one hour per level. Worse, each hour without the ability to access his own healing factor (natural or superpowered) means that the target must make a saving throw each hour (14+) or lose 1D6 HP as his own slowed life processes make greater and greater demands on his body.