Devil Slayer Magic

Devil Slayer Magic (滅悪魔法, Metsuaku Mahō) is a Caster, Lost Magic, and finally, a subsection of the Slayer Magic line utilized by those known as Devil Slayers (滅悪魔導士 (デビル・スレイヤー), Debiru Sureiyā lit. Demon Destroying Magicians). Originally, there was not much revealed about this magic—to the point that some people thought that it was a Curse known as the Devil Slayer Curse (滅悪呪法, Metsuaku Jūhō); however, as of recently, it was discovered that it is indeed a magic, and an extremely powerful one at that. The people who use Devil Slayer Magic in battle are known as Exorcist Mages (悪魔祓いの魔導士, Akumaharai no Madōshi).

Description
In order to learn the Devil Slayer Magic, the user must have their magic "modified" by one of the Books of Zeref, which contain notes on how to obtain Magic Barrier Particles, very similar to that of a Dragon teaching a human Dragon Slayer Magic. The Book of Zeref which passes on the Magic Barrier Particles of the element to the user modifies the user's magical origin with the book's own Magic Barrier Particles, inverted by the paper to not harm the user, which changes how magical energy circulates within their body, therefore causing their magic origin and own magical energy to become "demonic" in nature; thus a portion of their own power changes the user's magical power into that of a Devil Slayer. Continuing with this process, the (now harmless to the user) Magic Barrier Particles of book acts alongside the energy of the body in order to catalyze a variety of bodily processes when younger, therefore allowing the morphing of their physiology to a point where the individual has adopted some physical traits, as well as the element, from said book.

As a result of Devil Slayer Magic's mechanics, the user can transform their body with features of their respective element, utilizing both offensive and defensive styles; turning their body into a makeshift weapon unique to themselves. They can consume external sources of their respective natural element to replenish their own energy. A Devil Slayer Magic user is immune to the effects of their own element, and can consume external sources of their element to replenish their strength. However, as far as has been discovered, a Devil Slayer cannot consume the element that they produce themselves, and elements must be consumed through the mouth. Interestingly, out of the three "main" Slayer Magic styles, which consist of Dragon Slayer Magic. God Slayer Magic, and itself, it seems as if Devil Slayer Magic has the most power—as a user is capable of devouring the elemental magic of its peers. In addition to this absolute dominance over the user's element, they are capable of controlling the element of others with hand motions.

The user of Devil Slayer Magic is capable of modifying the properties of their element, morphing it from having immense cutting power to smashing into foes with incredible blunt force. The Devil Slayer Magic seems to surround the user with a small, barely felt aura of their own element—in one case, a user of Fire Dragon Slayer Magic noted how the temperature lowered after the appearance of an Ice Devil Slayer Magic user. Even though Devil Slayer Magic is capable of dealing immense damage against Etherious Demons and their Curses, a user of Devil Slayer Magic is unable to consume elemental curses, as they are composed of dangerous Magic Barrier Particles, whereas the regular Devil Slayer Magic's Magic Barrier Particles are considered harmless to the user. It should be noted that for Devil Slayer Magic, it is considered near impossible to learn for humans, as demons of any kind look down upon mankind, and it is unknown how Magic Barrier Particles can merge with a Magic Origin, thus making it an almost literal Lost Magic. Because of this, it was discovered that magicians are capable of learning Devil Slayer Magic from the Books of Zeref and the like, similar to that of how God Slayer Magic can be learnt from several books.

Trivia

 * This is the semi-official description for the Devil Slayer Magic, and unless Hiro decides to finally give out information (which he probably won't), and if it is consistent with what we have seen so far, than that information will be integrated within this page. (Hey, if Ashy and I did it for Curses in general, we can do it for Devil Slayer too).
 * As another note of trivia, before anyone complains, the reason that the Free Use template is on the top of the article instead of the Fairy Tail Wiki Content template is because the Admin of Magic, User:Perchan wrote the entire article (sans the kanji) by herself, nothing from the Fairy Tail wikia is located on the page. In addition, users have to ask her to create a Slayer Magic and Lost Magic anyway, so it works out in guiding new users.