You form a momentary link between yourself and the Negative Energy Plane that allows you to gain many of the traits common to undead creatures. You are immune to mind-affecting spells and abilities, poison, sleep effects, paralysis, stunning, disease, death effects, extra damage from critical hits, nonlethal damage, death from massive damage, ability drain, energy drain, fatigue, exhaustion, and damage to physical ability scores. You are immune to any effect requireing a Fortitude save unless it is harmless or affects objects. You need not breathe, eat, or sleep.
For the duration of the power, you have no Constitution score (—). You lose any bonus hit points gained from having a Constitution bonus (though this can't reduce your hit points to less than 1 per Hit Die). If your Consitution modifier is normally a penalty, you don't gain any hit points by manifesting this power.
Like an undead creature, you are damaged by positive energy effects and healed by negative energy effects.
You don't actually gain the undead type by manifesting this power.