Improved Two-Weapon Defense
You gain a significant defense advantage while fighting with two weapons.
Prerequisites: Dex 17, Two-Weapon Defense, Two-Weapon Fighting, base attack bonus +6
Benefit: When wielding two weapons (not including natural weapons on unarmed strikes), you gain a +2 shield bonus to your AC
In essence; with the two-weapon defense feat already in FK you get a +1 bonus to defence, with this this feat you would have an additional point on the top of that.