From Pathfinder Impossible Magic, which isn't enabled.

Bone Burst

FEAT 6

Activity reaction

Trigger A creature adjacent to one of your thralls uses a manipulate action or a move action, makes a ranged attack, or leaves a square during a move action it's using, and you are within 30 feet of the thrall.

You destroy the thrall in an explosion of bone shards that fly toward the triggering creature, dealing 2d10 (3d10 at level 12, 4d10 at level 18) piercing damage with a basic Reflex save against your spell DC.

The damage increases to 3d10 at 12th and to 4d10 at 18th level.

Pathfinder Impossible MagicORC