Frightful Blast

Warlock Invocation
Level: Least, 2nd lv.
Components: V, S
Casting Time: 1 standard action
Range: 60 feet
Duration: Instantaneous
Saving Throw: None
Spell Resistance: No

This eldritch essence invocation allows you to change your eldritch blast into a frightful blast. Any creature struck by a frightful blast must succeed on a Will save or become shaken for 1 minute. A shaken creature struck by a frightful blast is not affected by the shaken aspect of the blast but takes damage normally. Creatures with immunity to mind-affecting spells and abilities or fear effects cannot be shaken by a frightful blast.

(Complete Arcane, Page 134)