Blood Rage

When Frank is gravely injured and not well fed on blood, he will go into a Blood Rage. When he does, his mind is gone and he becomes a monstrous, killing machine. He tears his victim's limb from limb and drinks their blood. He cannot usually be calmed down when this happens so it's best for his friends to stay clear until he tires himself out. However, Bonnie was able to quell his rage once before during his attack against Abraham's army.

The cause of this rage is from his demonic heritage, a gift from his father. Many vampires can lose control when not feeding properly but none look the way Frank does nor have the power he has when he goes into a rage.