Kamikaze

You're a very reckless person, and your actions show it.
This Feat reduces your AC by 1, and if a character attacks you within your movement range, you can use your reaction to dash and counterattack with advantage.
When you enter a creature's attack range, you can attack with the same action. Whatever die you roll for your melee attack, roll an extra die for this attack.
When you leave an enemy's attack range, you get disadvantage on saving throws for 2 turns.