Great Weapon Mastery

You've mastered putting the weight of a weapon to your advantage, letting its momentum empower your strikes. You gain the following benefits:

• On your turn, when you score a critical hit or reduce a creature to 0 hit points with a melee weapon attack, you can make one melee weapon attack as a bonus action.
• While you are wielding a two-handed light- or vibro-weapon with which you are proficient, when you miss with a melee weapon attack, you can use your bonus action to repeat the attack against the same target. Any modifications to the original attack roll, such as advantage, disadvantage, or without your proficiency bonus, also affect this attack roll. On a hit, this attack deals kinetic damage equal to your Strength modifier.
• You have advantage on ability checks and saving throws to avoid being disarmed.
• While you are wielding a two-handed light- or vibro-weapon with which you are proficient, before you make a melee weapon attack, you can choose to forgo your proficiency bonus. If the attack hits, you add twice your proficiency bonus to the attack's damage.