Two-Weapon Rend (Mythic)
Your synchronized dual attacks are even more dangerous, and can leave lasting wounds.
Prerequisite: Two-Weapon Rend.
Benefit: The damage of your Two-Weapon Rend increases to 2d8 points plus twice your Strength modifier. You can expend one use of mythic power to gain a bonus on this damage equal to twice your tier.
Source: Mythic Adventures, p. 76