Two Weapon Mastery

When you take this feat you get the following abilities, making you a true dual wielding master.

• Destabilise: You can use your bonus action to make an attack that deals half damage. If the attack hits the target has disadvantage on the next attack it makes
• Defensive Flourish: While you are wielding one weapon in each hand, other creatures provoke an opportunity attack from you when they enter the reach you have with those weapons.

(This feat assumes you are using the following rule for two weapon fighting: Whenever you take the attack action - and you are holding one light weapon in each hand - you can make an additional attack with your off-hand weapon. (Two weapon fighting style and Dual Wielder feat apply as usual.))