Spirit Energy comes directly from the person's life force. It's a natural energy that sharpens one of the mutant's senses (such as enhanced hearing, sense of smell, touch, taste, and eyesite only one though). Spirit energy also allows the user to control natural element's (such as water, earth, fire, wind, etc). Spirit users (also called spirit warriors) also have what's called a "spirit awareness" that enables them to breifly see things before they happen. This tactic is very usefull in combat, as it allows them to dodge attacks better. This ability also helps them escape from danger. However there are ways to counter it. Such as moving lightning fast or use a ablity that can seal their energy from within. Feelings can sometimes cause spirit power to grow. Sleeping also helps spirit energy grow as well (because when your asleep, your mind is more opened and you can interact with nature better).