With blackwater mind, you surround your mind in mental patterns inspired by the blackwaters of the ocean depts, confusing and distressing those who try to telepathically contact your mind.
Anyone who attempts to manifest a telepathic power that targets you must make a Will save (DC equal to this power's DC). Those who fail the Will save suddenly find themselves trapped in what seems to be a smothering, lightless place of unimaginable pressure and bitter cold. Such targets are dazed, shaken, and blinded for 2d6 rounds.
This power does not actually protect from telepathic intrusion; rather, it is an attack triggered in response to a telepathic intrusion by another. You might still be affected by the attacker's power, even if the attacker is in turn affected by yours.
The only clue that you have activated this power is the momentary darkening of your eyes, which turn a deep black hue, like the seas' abyssal depths.
For every 2 additional power points you spend, you gain a +1 bonus on saving throws to resist any powers that trigger the blackwater mind.