Twist The Blade

You can deal additional damage on a sword hit. You gain the following benefits:

• When you take the Attack action and land an attack with only a shortsword or longsword you can use a bonus action to deal an additional melee attack by twisting the weapon to make an additional cut. This attack uses the same ability modifier as the primary attack. The weapon’s damage die for this attack is a d4, and it deals slashing damage.
• When you are wielding a short sword or long sword and are critically hit, it provokes an opportunity attack from you as you take advantage of the moment to cut the attackers nearest limb.