Keen blows

You've perfected the arts of precise attacks over the course of your lifetime, with enough grueling training, you hope to one day, strife to knock out anyone with just a single blow.

When you make an attack and succeed, you can activate your feat and force the target to roll a DEX saving throw, Upon a failed roll, the target takes an extra 1d6 + STR bludgeoning dmg, Or slashing depending on your method of attack. however, upon a failed save, the enemy gets temporarily stunned and cannot move until the beginning of its turn and cannot make opportunity attacks.

when using this feat with a ranged attack, it works the same as with a melee, however, the damage scales with your DEX rather then STR, so then it would be 1d6 + DEX. and then, when a roll succeeds, the targets movement speed is halved and has disadvantage on skill checks, saving throws, and death saving throws.

whenever you have an advantage attack, the 1d6 becomes a 2d8.