The psionic entity living in your mind enables you to better resist attacks.
Benefit: A psionic entity takes up residence within your flesh. The entity grants you the following psi-like ability:
Psi-Like Ability: 1/day—force screen or empty mind. Manifester level ½ your HD; save DC 11 + your Cha, Int, or Wis modifier.
Special: You can use one or the other of your entitygranted psi-like abilities once per day—you can’t use both. Once you use one, you can’t use the other for the rest of the day.
Source: Complete Psionic, page 60.