3rd-level / Tiger Claw
As part of this maneuver, you make a melee attack against a single opponent. If this attack hits, the target must make a successful Constitution saving throw or it takes an additional 1d8 points of damage from any attack until the end of your next turn. If your attack is a critical hit, this effect last for a number of rounds equal to your proficiency bonus. Your target takes normal damage from your attack regardless of the result of the save.