Blood Frenzy

You have a sense for blood, after wounding a creature you can smell their blood up to 60ft. 

If you bloody a creature you can use a bonus action to go into a frenzy for 1d4 rounds or until the bloodied creature dies

If you become bloodied you must make a wisdom saving throw of 15 or you go into the frenzy state for 1d4 rounds blindly attacking anyone within melee, if no one is in range you forgo your turn. At the end of the 1d4 turn you must make another saving throw, if failed you go another 1d4 round in this state. If someone enters melee range the provoke an attack of opportunity. 

when you are in the frenzy state you gain:

advatage on attack rolls

advantage on strength and dex saving throws

resistent to bludeoning attacks

consume blood to gain 1d6 of health

does not work on undead