Maneuver - Polearm required - If you are airborne and directly overhead of your target at the end of your movement, you may dive weapon first into the target as an action. On a successful attack, gain an additional d6 for each 10' of the dive. You make a Dexterity save, DC = to the falling component of the damage. On a failed save, you take half the damage as if you had fallen from the height. On a successful save, no damage is dealt. On a failed attack roll, take the falling damage without a save.

Save DC = tp 10 + 1 for each 10' of the dive. Drop the damage on a failed attack - just make it full or half damage, rather than 1/2 or no damage.