You can perform one additional parry per turn with a buckler or a light shield at your full attack bonus. If you have Two Weapon Fighting Improved or Two Weapon Fighting Greater feats, the amount of granted additional parries is further increased by 1 for each of those feats.
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Shield_Mythic_BucklerParryFeature
Your shield hand is moving with lightning speed, able to deflect attacks coming from every direction.
When you fight while using Shielded Defense, only every second incoming attack reduces the AC bonus granted by the ability.
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Shield_Mythic_ShieldedDefense