Hindering Song (Feat)
Your performance is so compelling, so magical, that all opposing magics must struggle to compete.
Prerequisites: Level 31, Bardic Performance class feature, Deafening Song, Perform 24 ranks
Benefit: During any round in which you use a Bardic Performance, your performance creates an Aura centered on your space with a 30-foot radius. This aura interferes with all enemies who attempt to use a Spell-like (Sp) or Supernatural (Su) ability. Once activated, this aura persists until the beginning of your next turn.
To successfully use a spell, spell-like ability, or supernatural ability within this area, an enemy creature must make a Caster Check to Concentrate as if they were casting defensively, versus a Challenging skill DC based on your highest Bard level. Creatures which fail this check lose that use of their ability, just as if they had failed a Caster Check to Concentrate to cast defensively.
You can choose to exclude as many creatures as you wish from this effect. Hindering Song is a performance, and requires entering and sustaining the performance stance, just like any other performance.