Chakra
Chakra, like health, is a strange and abstract concept. Basically, this is the magical energy that your body has that allows it to perform super human actions. Chakra is closely tied to the body's basic needs, and much like stamina, if you run low on it your body begins to suffer from exhaustion. Just like stamina as well, if you run out of chakra your body will shut itself down and you will reach an unconscious state.