Mind Drain( Complete Scoundrel, p. 79)
Your attack can weaken your opponent's mental powers.
Your successful sneak attack drains power points from your target equal to its manifester level (minimum 1). If this attack reduces your target to 0 power points, the opponent also loses any psionic focus. A target that has no power points when you make the sneak attack is not affected by this feat. You can't use this feat on the same target more than once per round. Using this feat reduces your sneak attack damage by 1d6.