Thri-Kreen Multi-Weapon Master (5e Feat)

Prerequisites: You must be a thri-kreen.
Born with four arms, you have learned to fight using all of them at once. You gain the following benefits:

The lower arms granted by your Multiple Limbs feature can now be used to attack, as described below.
Whenever you take the Attack action during your turn and attack with either an unarmed strike or a melee weapon you are wielding with one hand, you can use a bonus action to attack with either unarmed strikes, or light melee weapons you're holding in your 3 other hands, to a maximum of 3 additional attacks in total from your extra arms. These attacks have a -2 penalty to their attack rolls.
Fighting so extensively with your lower arms forces you to leave yourself open or move into extremely close range. Each time you hit with the attacks granted by this feat, until the start of your next turn enemies have advantage on attacks made against you.