Mana

Mana exists in all things, the air, the earth, the water and every single plant and living being.
It is the magical energy that permeates Araban and grows the strenght of its inhabitants beyond limits of what would otherwise surely be impossible
It makes physical and magical powers possible and so much more.
Mana itself makes it possible for elementals to manifest from nature as well as give sentience to non-humanoid beings and is the reason why the natural resources of the world resupply themselves to seeming infinity, allowing wars to last far longer than would otherwise be possible.
The only real way to negate mana is by using magic or Anti-magic to dispel it from an area thus making a permanent or temporary magic dead-zone.
In Nature: In Araban's nature, mana flows through the world mostly unseen though there are ways to perceive it with the naked eye, which is a light blue mist in the air, existing much like water does in air, forming particles that are unfelt by the regular or even a trained person. It exists in the very structure of rocks and trees and all inorganic matter, not only reinforcing the materials but granting them mystical qualities, granting life or sentience or imbuing them with abilities or features that make them more unique, often engaging in random evolution of any given subject, providing infinite possibility.
In Crystallization: Sometimes Mana does only permeate the air but solidifies into a Crystal form, these Mana Crystals are often imbued with powers of mana, capable of doing all sort of things such as allowing untrained people use magic, call forth beings or have access to other abilities, such as physical enchantment. Being mana Materialized, these gem stones and crystals were eventually named 'Materia' by an ancient sage of a bygone age. It is often said that the kingdom with the most materia wins, as they are easier to use than training spellcasters, however since Materia drains mana from its user, untrained people can quickly run into exhaustion or in the worst cases, Death.
In People: Mana co-exists with Chi in a humanoids body, working like two separate sources of power and enforcement. Where as Chi must be trained and honed from within, Mana pours out of a person at all times and fosters them passively as time goes, though for most people this passive growth is negligible and not useful in any practical way, it is possible to train and hone a persons mana to higher stages, unlocking more capability and usage out of it.
Facing dangerous situations, fighting, self reflection with ones mana and magical power, training and practice are only some of the ways how to further hone ones skill in mana use.
Mana does not by itself do much to a person as it is magical energy, it is most often used by the denizens of Araban to boost physical protection or striking power, or more commonly used to invoke arcane or otherwise magical spells or effects. Mana itself coats a persons body naturally and althought this thin layer is unseen and unfelt by all people, it protects denizens of Araban from harm to some extent. Helping people survive (althought barely) even otherwise mortal blows, linger way more than other people as they are dying, or even eventually manifest regenerative capabilities.
Although generally Mana only makes a regular Araban human more durable physically than humans of other worlds, it is still a notable difference. Although mana exists in everyone, cultivating it is simply impossible for some people whose Mana growth rate is too nil to amount to any ability, or their own ability of manipulating their mana never truly manifests.
People with large amounts of Mana are called to be 'Blessed by Mana' who either cultivated massive amounts through hardships or were born with amounts unfair.
Because all humanoids are born with different amounts of mana, the civilizations of Araban usually employ a small ritual in early childhood to use arcane means to check their inborn mana amount, to indicate if they will be capable of using magic. However these tests are not perfect, and thus someone who is judged to have no magical potential may develop such skills later in life, although of course, those born luckier have an advantage over such people.
Application & Use: Humanoids manifesting Mana can 'feel' their own Mana reserves and pull on them mentally, releasing an effect of magical nature. These skills are often restricted by Spell and Incantations based upon magically created effects that spellcasters have formed through mana with years of spellwork gone into it, honing and focussing what would otherwise be random and chaotic mayhem.
For an example, a trained spellcaster will have access to spells from tomes and through training, memory. A spellcaster without training could most likely cause harm, push people away or manifest an effect based on -intent- by utilizing their mana, although some rare genius might make a spell just by accident if their intuition was sharp enough, with their creativity. This is however extremely rare.
The Elements: The elements include Light, Shadow, Lightning, Fire, Earth, Water, Wind and most spell pertaining to them are taught as recognized spells, as long ago in history wise mages were capable of translating the spells and mana used by the Elementals that manifest in the world, creating spells with them, although these are far from all magic in the world. Blood and Ice are sub elements of the element of Water, for an example. While Lava is a combination of Fire and Earth. More combinations exist as well. Mixing elemental magic is also possible, such as water and fire.
Anti-Magic: In itself Anti-magic of Araban is a contradiction upon itself, as to pursue Anti-magic is to use Mana to form an area, construct or other means that devours Mana until there is none left in an individual, area or item, thus erasing the force that made it and killing the world. The use of it weakens anything it touches, though in most cases the effect is temporary as people have a refilling reserve of mana, and nature oozes in new Mana, the truly permanent Anti-magic is something truly terrifying and perhaps even worse force than Death. The unexistance of all things.
Kaos: The forces of Kaos are a unique type of magic that is completely random by its own nature, creating random and terrifying effects, which makes it about as dangerous to the user as it is to their enemy. This is why usually even demons do not use it willy nilly although it is very powerful. It is sometimes refered to as Wild magic by some.
Negative & Positive Energy: The two magics utilized by both the Celestials and the Demons, positive energy either heals their targets or sears their enemies, while Negative energy negates wounds and cripples and evaporates enemies. These malleable holy and unholy magics see rarely use by mortals, though if they do, they are powerful indeed... This magic is also named divine magic, unholy magic and other such monikers. 
Necromancy & Puppetry Magic: The art of Manipulation is also one of many applications of mana, in the case of puppetry or necromancy, the user uses their vast amounts of mana and through dark arts forces it into the bodies of living or dead people, commanding them to move. In the case of undead, the user can even place a faux soul inside the corpse to make it move on its own to the users will or commands, or even pull the corpses own soul back into its shambling body. Puppeteers can also make faux souls to take over the body for the duration of their manipulation, though this is temporary.
Arcane: The most basic form of Magic is truly the arcane, the very same mystical energy that Mana itself is, this was most likely the very first type of magic ever discovered by intelligent races and its applications are vast, from opening locks to teleporting yourself miles away, or calling meteors down from space to crush your enemies, or creating transdimensional pockets.
Force of Infinite Possibility: Magic and Mana are based very much on the people they are used by as much as the doctrines those users follow, granting this power near infinite possibility on how it is wielded or what form it takes... Every person wielding magic is unique, so too is the power that they wield or create. It is likely that documenting all forms of magic is truly impossible.

Manifestation

The most common manifestation of Mana is when it is used in arcane spells or very powerful physical individuals perform feats of strength.
In the wild it can manifest as light blue mist or become crystallized into a blue crystal form. Mana potions themselves are blue liquid mana. It is a magical energy that grows in all beings and natural states.

Localization

Mana exists everywhere on Araban and in all things, aside from the use of anti-magic, mana is a constant in the world.

Type

Metaphysical, Arcane