LifeForce and anti-LifeForce
LifeForce is simply the anima of an individual, the source of their vitality, energy, spirit, and strength. Many creatures in the BrikVerse thrive on this energy, survive by devouring this energy, or are adept at manipulating this energy. It is seen as a toy or a curiosity mostly and is not given much consideration beyond its utilitarian qualities.
Anti-LifeForce is the opposite of life, the energy of death. It is most commonly found as the animating spirit of the Undead. It is treated in much the same way as its counterpart: as a tool.