Your magical energies cling to enemies, interfering with their spellcasting.
Benefit: Targets affected by a disruptive spell must make concentration checks when using spells or spell-like abilities (DC equals the save DC of the disruptive spell plus the level of the spell being cast) for 1 round. Targets that avoid the spell’s effects avoid this feat’s effect as well.
Level Increase: +1 (a disruptive spell uses up a spell slot one level higher than the spell’s actual level.)
Advanced Player’s Guide. Copyright 2010, Paizo Publishing, LLC; Author: Jason Bulmahn.