Antagonist( Complete Psionic, p. 60)
The psionic entity you host seeks to cause damage and mayhem, and you have powers to further that end.
A psionic entity takes up residence within your flesh. The entity grants you the following psi-like ability: Psi-Like Ability: 1/day--energy ray or crystal shard. Manifester level 1/2 your HD; save DC 11 + your Cha, Int, or Wis modifier.
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.