Vesper Primer+Standard Actions+ Defensive Whirl

Sphere: Dual Wielding
Duration: 1 round
-7

Whenever you use an attack action and successfully strike a single creature with both your main-hand and off-hand weapons, that creature takes a -1 penalty to all attack rolls against you for 1 round. For every 5 points of base attack bonus you possess, this penalty increases by an additional -1.