Two-Weapon Rend

Dex 15, Two-Weapon Fighting, Improved Two-Weapon Fighting, base attack bonus +9

When wielding weapons in both hands, if you hit an opponent with both weapons in the same round, you may immediately rend that opponent for additional damage. Rend damage is equal to the damage dealt by your off-hand weapon as if it scored a critical hit. You add 1 ½ times your Strength modifier to damage rather than only half.

You do not roll to attack; rend damage happens automatically when you choose to activate it. This is not considered a critical hit, so effects that trigger on a successful critical hit are not triggered and creatures not subject to critical hits still take the extra damage.

You can only rend once per round, regardless of how many successful attacks you make.

For creatures with more than two arms, this feat may be triggered when you hit an opponent with any two or more weapons (wielded in different hands) in the same round. Rend damage is based on the first off-hand weapon to hit, regardless of how many off-hand weapons successfully hit that opponent.