SRD:Duodimensional Claw

If you have a claw attack (either from an actual natural weapon or from an effect such as claws of the beast), you can use this power to improve that weapon. One of your claws becomes two-dimensional, making it razorsharp. The weapon is now psionically keen, increasing its threat range from 20 to 19–20. This benefit does not stack with other effects that improve a weapon’s threat range.

The third spatial component of your hand still exists but is temporarily shunted into the Ethereal Plane, so against ethereal or incorporeal targets this power is ineffective.