Black Tentacles

Add your tier to the base attack bonus of the tentacles. The tentacles also deal an additional 2d6 points of acid damage with a successful grapple.

Augmented (6th): If you expend two uses of mythic power, the spell creates twice as many tentacles in the same area, meaning each creature in the area is attacked twice per round. The tentacles can grapple creatures that are immune to grappling if that immunity is from a non-mythic source, but combat maneuver checks to grapple such creatures take a –5 penalty.