Dragon Slayer

Dragon Slayer magic (滅竜魔法 Metsuryū Mahō) is a specialised form of magic which the series suggests can only be learned from the dragons themselves. Dragon Slayer allows the user, to a certain degree, transform their body into that of a Dragon. As a result of this, those with Dragon Slayer abilities are able to change their body to their own element, in both offensive and defensive styles. Because their own bodies can function as make-shift weapons unique only to themselves, Dragon Slayers are typically unarmed fighters who excel in physical combat and relying only with their magic. They can also consume external sources of their natural element to replenish themselves, although it has been demonstrated that certain foreign substances will substantially increase their power, i.e. Natsu's consumption of Etherion greatly increases both the strength of his body, and his magic. They are also naturally immune to the effects of their own element that came from both their own person and those from other sources, but must consume it through their mouths if they are to actually absorb it into their bodies. Dragon Slayers also have an incredible sense of smell too. There are "Old-style" Dragon slayers, the true practitioners, who learn from dragons and "New-Generation" Dragon Slayers, who implant Lacrima crystals into themselves, although it is only an imitation of the magic, according to Cobra, though this has yet to be proven true, as he may make this up to confuse and insult Natsu.

Dragon Slayers are apparently quite rare; often, only a single one can be found within the membership of a single guild. Making the Fairy Tail Guild very unique as it has three on its roster

Apparently, Dragon Slayer Magic has limitless functions in Edolas, and is valued as a priceless resource for everyday uses.

"Why would a dragon teach another person how to beat dragons?"

- Lucy asks what we're all thinking, Chapter 1

Original Dragon Slayers
Dragon Slayers who have been raised by a dragon and taught their abilities.

Fire

 * Dragon: Igneel
 * Known User(s): Natsu Dragneel

A Dragon Slayer ability which incorporates the element of fire into the user's body.

This allows the user to produce flames from any part of their body, including their lungs, giving them the ability to, in essence, breathe fire.t also allows the user to consume external sources of fire to restore their body to a healthy state, meaning that they cannot use their own flames to renew themselves.

As well as the added benefits of their elemental advantage, the Dragon Slayer magic gives the user a much greater level of endurance.This in turn is greatly enhanced by the consumption of Etherion, which not only boosts physical strength and magic, but also causes a layer of hardened scales to appear on the user's body. However, due to the poisonous properties associated with the crystal, it is considered highly dangerous to take the substance into the body, regardless of the benefits.

Spells:
 * Fire Dragon's Roar
 * Fire Dragon's Claw
 * Fire Dragon's Iron Fist
 * Fire Dragon's Wing Attack
 * Fire Dragon's Sword Horn
 * Fire Dragon's Brilliant Flame
 * Fire Dragon's Flame Elbow
 * Fire Dragon's Crushing Fang
 * Flame Lotus: Fire Dragon Fist
 * Flame Lotus: Exploding Flame Blade
 * Flame Lotus: Phoenix Sword

Iron

 * Dragon: Metalicana
 * Known User(s): Gajeel Redfox

Gajeel Redfox knows Dragon Slayer magic because he learned it from the dragon Metalicana. His Dragon Slayer magic deals with metal instead of such elements as wind and fire. Like Natsu eats fire to regain strength, he can eat his respective element to regain his strength. Gajeel's magic seems to deal with producing multi-sized iron rods as well as changing parts of his body into steel. Most of his attacks involve transforming his arm/s into hard-as-steel weapons, which he can do at will.

Spells:
 * Iron Dragon Scales
 * Iron Dragon Roar
 * Iron Dragon Club
 * Iron Dragon Blade
 * Iron Dragon Spear: Demon Firewood
 * Iron Dragon Hard Fist (Anime only)
 * Karma Demon: Iron God Sword

Sky

 * Dragon: Grandine
 * Known User(s): Wendy Marvell

Wendy is the Dragon Slayer of the Sky, which means that she uses old-style dragon slayer magic like Natsu and Gajeel. According to Charle, Wendy cannot use her magic in highly polluted areas. It is said that Sky Dragon Slayer magic actually focuses more on healing than damage which is impressive in its own right since true healing magic apparently has been lost. She has yet to be seen using this ability for the most part. As of now, Wendy has only shown support magic that boost her allies or her own physical abilities as well as basic first aid spells like detoxification. Her only known offensive spell is Sky Dragon Roar.

Spells:
 * Troia
 * Sky Dragon Roar
 * Vernier
 * Arms

New-Generation (Artificial)
Dragon Slayers who have Dragon Lacrima implanted into their bodies. It is suggested that while they have vast power, they don't have the potential of true Dragon Slayers, as any Old Style has defeated a New Generation Dragon Slayer. However, it should be noted that it took both Gajeel and Natsu combined to take on Laxus, so that might have been more a show of Natsu's potential rather than the difference between New and Old generation itself.

Lightning

 * Known User(s): Laxus Dreyar

Technique(s):
 * Lightning Dragon Roar
 * Lightning Dragon Heavenward Halberd
 * Lightning Dragon Breakdown Fist (Anime only)

Poison

 * Known User(s): Cobra

Technique(s):
 * Poison Dragon Roar
 * Poison Dragon Twin Fang

Dragon Force
Dragon Force is when a powerful Dragon Slayer starts to turn their own body into a humanoid dragon. Dragon Force gives the user a huge power up and almost makes the user unbeatable. According to Zero, it is the most powerful and final state a Dragon Slayer can attain. It increases the damage from standard Dragon Slayer attacks. It causes their body to cover in scales and their magic aura to become visible, taking the shape of a dragon. For Old-Style Dragon Slayers, certain conditions must be met in order to achive Dragon Force state; the only one known so far would be to eat substances with powerful magical properties, preferrably those related somehow to the element they can control and consume. Natsu (through consumption of Etherion and from the Flame of Rebuke), is one of the three True Dragon Slayers to activate this power. It is likely, given the description as the final state a dragon slayer can attain, that a dragon slayer may eventualy gain access to it without outside sources of power.

Trivia

 * Before "Dragon Force" was named, fans called it "Dragon Slayer mode"
 * Zeref shows some characteristics of an old style Dragon Slayer. Whether or not he is one is still unknown.
 * Out of all the currently known Dragon Slayers, Wendy is the only one who hasn't lost to Natsu