[Five points of death] - Five points that are located on the body of every being dead or alive, and inanimate objects. When one of these points are hit with a ma.s.sive amount of force, it will cause the person to break apart internally. They are the absolute weak points. These five points have no distinct location as everyone/object has these points in different areas.

[Essence Pool] - A pool made up of concentrated essence. Used to help increase the rate at which an EXO user absorbs essence.

[Equipment Grade] - Equipment can be can be broken down into five different grades. Basic/Medium/Advanced/Legendary/Mythical, each with a low, mid, high tier. Higher grade weapons have a higher durability and deal more damage. Some weapons enhance a certain EXO ability, while others just increase the flow of EXO essence to the weapon.

[Beast Ranking] - Beast are all ranked and have a certain tier. Omega/Beta/Alpha are mutated beast of the lowest ranking. Demon ranked beast are graded by numbers, with the highest being a grade five and lowest being grade one. After Demon rank is, Demon General which has the same grading system as Demon. Demon Lord is next, with only three grades in that rank. Finally, Demon King. There are only seven Demon King beast in the world. However, there have been tales of there being a Demon G.o.d. No beast has come to that rank, since

[Essence Depletion] - When an EXO user is killed all the essence in their body is drained. An EXO user can be drained of all the essence in their body as well under certain circ.u.mstance, causing them to look old and wrinkled.

[Guardian Family] - The strongest family in a country, that is responsible for foreign affairs and government management. Members of the Guardian Family all become high ranking officials of society or the military. If a war breaks out they will be on the front lines.

[Shadow] - Shadow is comprised of students at Demeter Academy who are in the Student Council and Disciplinary Committee. Shadow undertakes task that are similar to the special forces but on a smaller scale.

[Crow] - Substance made of pure essence that has been mixed with various chemicals. Highly unstable, but is used/traded on the black market.

[V-State] - Darker path EXO users can take. The pure essence in your body is more demonic and your power is strengthened. The only way to achieve this state is to exchange your life for it. Who grants a user this power is currently unknown.

[Modified Human] - Humans who have undergone a surgery to enhance themselves.

[Genetically Modified Human] - Humans that were produced in as a lab experiment. Each one of them has more than one EXO ability. These abilities came from Demon ranked or higher beast. They have no father, and all of them are under the control of Delirium except for Katherine.

[Self-Evolving Specimen] - Using Diana Wells data they recovered, the Wells started a new experiment. Mary Wells tweaked her cousins work with her own knowledge to create a new specimen/being. With the help of sub-branches they managed to produce four Self-Evolving Specimen.

S.E.S are able to learn on their own and advance at a rapid pace. Without any sort of training their essence will grow exponentially. They have the ability to duplicate other EXO and they can shapes.h.i.+ft.

[Spirits] - Beings made up of essence. The only ones who can see spirits are Spirit EXO users. However, there are a few exceptions. Spirits come in different shapes and forms.