Jsk Feats:Heavy Weapon Master

You've learned to deliver crushing blows using mighty weapons. You gain the following benefits:
 * When you are wielding a heavy weapon in both hands, you gain a +1 bonus to your AC.
 * When you make a weapon Attack with a heavy weapon, you can choose to reduce your speed for the turn to gain a bonus to your attack roll. For every 10 feet you reduce your speed, you gain a +1 bonus to your attack roll, to a maximum bonus of +5. If you make an Attack with a bonus of at least +3, you score a critical hit on a roll of 19 and 20.
 * If you score a critical hit with a heavy weapon, the target of that attack must make a Strength saving throw against a DC equal to 8 + your proficiency bonus + your Strength or Dexterity modifier (your choice). On a failed save, the creature is knocked prone and takes additional damage equal to your Strength modifier (a minimum of 0).