Fueled by Blood

You were specially designed by your creator to have armor plating that absorbs blood in order to fuel and automatically repair you, when you take this feat, you gain the following benefits:

Fueled by Blood: If you end your turn without dealing melee damage to an enemy, you gain 1 level of exhaustion

Bio-Repair: When you hit an enemy with a melee attack, you heal 1d8 for each enemy you've killed during that combat + half the amount of damage you've dealth

Overfuel: If you are at maximum hitpoints and receive healing, it becomes temporary hitpoints

Violent Refreshment: When you kill an enemy, remove 1 level of exhaustion