Beast of Butchery (Dexterity or Strength)

You fight without mercy, making short work of your foes in their moments of weakness.
You gain the following benefits:

• Increase your Dexterity, or Strength score by 1, to a maximum of 20. (sorry cant choose Charisma, had to make separate feats)
• You have advantage on opportunity attacks and attacks against creatures that are frightened of you.