As two actions, a tendril of inky darkness reaches out from you. When you cast the spell—and as an action on each of your turns thereafter—the tendril can touch a creature that you can touch or see within 18 meters to drain life from it. The target must make a Reflex saving throw.
On a failed save, it takes 5d4 necrotic damage.
On a successful save, it takes half as much damage.
Whenever the spell deals damage to a target, you regain health equal to half the amount of necrotic damage dealt.
You can increase the damage by 3d4 for each additional mana or psi expended.