Improved Back to Back (Teamwork)[]
After much practice, you and an ally have become adept at fighting in close proximity to one another.
Prerequisites: Back to Back, Perception 5 ranks.
Benefit: While you are adjacent to an ally who is flanked and also has this feat, you can spend a swift action to gain a +2 bonus to AC against all flankers until the start of your next turn.
Essentia: this bonus increase by +1 / Essentia