Quinary
As more damage is taken, they begin to smoke and visibly break apart, reducing accuracy and speed. But as long as their drive is connected to their chest, they cannot drop lower than 5 HPs (at least not normally). As their drive is attacked, it begins to come loose, gradually reducing all of their stats by up to 33%. Their drive becomes more vulnerable the less HPs they have, and when it falls off, they fall unconscious and die.