Everybody knows that living things are animated by energy. Many call it chi or qi, or lifeforce, animus, or prana. It's not quite the same as numen, which is more of a projection of the spirit, it is instead what moves and gives inanimate matter its life.
However, lifeforce is not so banal as to be one entity. Life force in proper balance and alignment, such as with the four humors or four elements, is focused and pure. It is white life force, which is gathered and spent by all living things. It is the natural force of life.
But there is more then just this kind of life force; life force that is especially unbalanced or too powerful for its mortal form is out of control; those with too much life energy may start to have their own negative symptoms. The same applies to ecosystems where magic or living energy has been introduced too quickly or without thought; a mass battlefield where hundreds of great hereos have been killed, or when a great ageless ocean leviathan dies and sinks to the ocean floor. This glowing energy is consumed by creatures who grow tumors and mutations from the excess power; these creatures are unstable but very strong and very dangerous.
However, some alchemists and mad-botanists may use this power to further their own ends. By collecting and refining it, it can be used in various alchemical or magical processes. Though it is best used fresh, long dead or unborn forms of this life force can be found in ancient urns, trapped within the eggs or seeds of unhatched monsters, and extracted directly from infused landscapes. There are three kinds of Lifeforce energy.
Wild lifeforce is energy tied to the most basic categories of things, and is about shifting or hurtling those limitations. Wild animals infused with Wild lifeforce are more aggressive then normal; many prey animals become predatory when infused with even a small amount of Wild, becoming ecosystem destroyers. Creatures that gain a large amount of Wild lifeforce gain the ability to create or even breathe fire, and it is thought that dragons have a higher then average amount of this life energy within them for this reason.
Wild lifeforce is highly tied to creatures like bears, tigers, elk, and rats- these animals are all generalists and prolific, filled with life in its most primal form. However, any animal or being can be infused with Wild lifeforce. If you consume a charge of Wild energy, gain +1d6 temporary hit points, +2 to damage, and gain nigh-limitless stamina for that day.
Vivid lifeforce is energy tied to the most basic and powerful traits of animals and plants, and is all about enhancing those properties and enhancing the special unique traits of creatures and beings. Vivid infused animals tend to develop venom and lightning energies, and can survive in an ecosystem that is too harsh for most living things, hence making them even more specialized. Many fantasy monsters, such as basilisks or gorgons, are heavily biased towards high concentrations of Vivid lifeforce, as this could explain their unusual powers and specilization.
Vivid lifeforce is highly tied to vermin, insects, reptiles, and overly specialized creatures; such as cave beings or deep sea monsters. However, any animal or being can be infused with Vivid lifeforce. If you consume a charge of Vivid energy, gain +2 AC and to hit, and gain ½ immunity to a random elemental damage type for the rest of the day.
Primal lifeforce is energy closest tied to the rules of the universe and magical power of all the life forces. Many consider Primal to be ur-mana energy, and most beings that cast spells have slightly higher concentrations of primal lifeforce in their blood and stool; the connection is obvious, thought it is unsure if this is the cause of their magic use or a result of it. Creatuers associated with primal energies include unicorns, elementals, and almost all birds. Primal also has strong associations with age and timelessness; many people believe birds were the first animals to every fly to the land from heaven, since their wings let them skip the long walk down, but in their hubris they were punished to forever sing the praises of God, instead of being silent and stealthy like most fragile creatures do.
Primal lifeforce is highly tied to flying creatures and magical beasts. However, any animal or being can be infused with Primal lifeforce. If you consume a charge of Primal energy, regain the lowest available spell slot you have expended, gain Infravision up to 30 ft, and count as uncumbered for the rest of the day as long as you do not try to carry over your encumbrance limit.