Indomitable Mountain Avalanche

If an opponent fails at a combat maneuver against you, you can use an attack of opportunity to make a melee attack against the opponent using your highest attack bonus. If the attack hits, instead of dealing damage, you can push the opponent back 5 feet for every 5 by which it failed its combat maneuver check (minimum 5 feet). Additionally, when you hit with an unarmed melee attack against an opponent who provoked an attack of opportunity by failing its Acrobatics check to move through a space you threaten, you can push the opponent back 5 feet instead of dealing damage. The opponent moves back in a straight line, but stops before hitting any obstacle or hazard.