The Devil of Zero

Disclaimer: Neither The Familiar of Zero nor Devil May Cry belong to me.

Glossary of Terms

Devil: The highest orders of infernal beings, Devils are the remnants of the traitorous Celestial Legions that followed Lucifer in the War in Heaven. Celestials of all kinds, from the lower Angels, Archangels and Principalities, through the Authorities, Virtues and Dominions, and even including members of the highest orders of Ophanim, Cherubim and Seraphim, all were twisted by the environment of Hell and the weight of their sin into hideous, grotesque forms. Despite being cast down, the Devils still retain much of the might they had as Celestials, giving them horrible power over aspects of the universe. Due to their might, the dimensional boundaries are especially binding against these monsters, keeping them from crossing into the Mortal Realm without the aid of a powerful summons or a Hell Gate.

It is believed that Sparda, the Legendary Dark Knight himself, was originally a Fallen Seraph who later reclaimed his history and fought against his former comrades during the Darkest Ages of Earth thousands of years ago.

Demon: The lowest dregs of Hell, the origins of the many species of Demons are varied, from interbreeding between once-segregated lines of Fallen Celestials, to once-human souls warped into unrecognizable beasts by the torments of Hell. Including the weakest of all Infernal Denizens, Demons are capable of crossing the barrier regardless of the presence of a Hell Gate, although they lose large quantities of power in doing so. By consuming large amounts of human souls, a Lesser Demon can become a Greater Demon, or a Greater Demon ascend to the ranks of the Devils. The environments most capable of supporting such evolutions are war-torn battlefields, both World Wars being notable in aiding the ascendance of almost three dozen Greater Demons into Devils.

Infernal Energy: A corrupt and insidious energy permeating the body of all Demons and Devils, Infernal Energy fuels the most powerful of their abilities and their twisted sorceries. Often the goal of a mortal summoning a Demon or Devil is to obtain a measure of this power, allowing them to further their own schemes.

Devil Arm: Weapons crafted from or imbued with the souls of Devils, Devil Arms are created whenever a strong-willed being slays one of the Fallen and binds the damned one into a form suiting its abilities and magic, forcing the Devil into the service of whoever can match or exceed their willpower. One who wields the Arm of a Devil can call upon its awesome powers to aid them in battle. Mortals be warned, for even constrained so, the Devil inside can still corrupt the unwary. Examples include Force Edge/Sparda, Rebellion, and Yamato, respectively the Devil Arms of Sparda, Dante and Vergil.

Devil Trigger: One of the most potent tools in the arsenal of a Devil is the ability to trigger a transformation of its physical form, using Infernal Energy to fuel the enhancement of its most basic attributes, including strength, speed, regeneration, and toughness. The form shown by this transformation is the truest expression of the Devil's very soul. The Devil Triggers of the Sparda Twins are unique because of both their youth and mixed heritage, being unstable and taking on the qualities of whatever Devil Arms they wield at the time. With age and experience, they cement their souls and achieve a more stable and powerful Devil Trigger.

Desperation Mode: A technique of last resort, this is a cheap imitation of the Devil Trigger, used by Demons in times of great peril and personal danger. When a powerful Demon finds itself grievously wounded and assailed on all sides, it channels its Infernal Energy back into itself, empowering its strength and speed by a great margin. Used unwisely, this can mean a very final end for the Demon, as it can devour their very soul in supporting their body if left unchecked.

Sorcery: The magic of the Fallen, Sorcery uses Infernal Energy to effect changes upon the universe, differing from the innate abilities of Devils and Demons in that any competent being can use any Sorcerous Technique, so long as they hold the Infernal Energy required. Some examples of Sorcery are Vergil's Summoned Swords, the Spardas' Dimensional Armory, and Dante's Infinity Shot.

Celestial: An inclusive, generic term referring to all the denizens of Heaven, Celestials are grouped into three spheres, each consisting of three ranks. From lowest to highest, these are the Third Sphere, consisting of Angels, Archangels and Principalities; the Second Sphere, consisting of Authorities, Virtues and Dominions; and the First Sphere, consisting of Ophanim, Cherubim and Seraphim. Inside of each rank are different species with various forms to suit their functions, with two different factions: The Guard, which are the most humanoid Celestials that fit the preconceptions of mortals, intended to deal with external matters, such as Earth and Hell; and the Laguna, the more bestial and strangely formed Celestials intended to deal with internal matters regarding Heaven.

Grigori/Watchers: Disgraced Celestials that lusted after mortal women and copulated with them, birthing the Nephilim race and beginning the Trinity War between Hell, Heaven and the Nephilim. Rather than casting them down into Hell as with Lucifer and his confederates, the Grigori were chained and forced to Earth with the mortals they sinned for, their greatest powers sealed for all eternity.

Nephilim: Half-Celestial, half-mortal beings with terrible power, individually unmatched by Celestial or Infernal. This race started a centuries-long war with Heaven and Hell, wreaking havoc and spreading destruction until the Infernal and Celestial armies finally cornered and fought them down to the man, leaving only four left that pledged servitude to the Council, the mediators of Reality.

Purgatory: A sort of sub-Realm within a Realm, Purgatory is the medium through which Celestials act within a Mortal Realm while remaining unseen, while allowing them to interact with the primary Realm both physically and magically. Through this dimensional film, Celestials observe a Mortal Realm, scouting and spying out any signs of Demons in order to hunt them down and kill them, and for a long time, Purgatory was the Celestial's trump card over the Infernals. Until said Infernals helped found the Umbra Witches, who created Sorceries to break into Purgatory, and the Devils created the Limbo Sorcery.

Limbo: An Infernal clone of Purgatory, Limbo is a dimension created through a Sorcery that is powered by a Hell Gate or something of similar potency. Similar to Purgatory, beings within Limbo are invisible to those in the primary Realm, although unlike Purgatory, they are also intangible. Limbo is also distinct from Purgatory in that the caster of the Sorcery can control the dimension in any number of ways, warping its internal reality to alter any aspect of the environment including gravity, form and function. Also unlike Purgatory, beings within Limbo can forcefully pull others into it, subjecting them to the whims of the dimension's owner and allowing them to be attacked by those within Limbo.

Magic: The ability of Halkeginia's nobles to manipulate the very elements of creation, magic uses a mage's willpower to focus and shape the elements of Fire, Earth, Water, and Wind to create an effect in reality, using incantations and a foci to concentrate and focus the mage's will. Every mage has an affinity for an element, the one with which they are best suited to use in their magecraft.

Mage: A practitioner of magic, mages are always of noble birth, and are said to have been gifted their abilities by God. Mages are ranked according to how many iterations of one or more elements they can use in a spell, ranging from Dot-class mages that can only use a single element, to Square-classes that can combine all four elements, four iterations of a single element, or anywhere in between to create astonishing effects.

Void: The Fifth Element of Magic, Void was the element of the Founder Brimir, the one who established Halkeginia's current system of magic. Void is considered to be the Lost Element, due to the fact that none since Brimir have used it in recorded history.

Familiars: The servants and companions of mages, familiars are considered to be integral in the development of a mage, and the ritual to summon and bind them is said to choose only the familiar best suited for the individual performing the rite. Often, the summoned familiar is a creature that is intimate with the summoner's elemental affinity.

- The Author -

For those new to both Devil May Cry and Familiar of Zero.

Note: The definitions here are not necessarily canon in regards to either series' respective universe, just the ones that I fell explain aspects of the backstory and certain parts of Devil May Cry's gameplay.

Edit: Added some entries in light of the future events I planned.
Edit 2: Added the Purgatory and Limbo entries in light of the backstory alterations I have to plan out