Dragon

Dragons (ドラゴン Doragon) are one of the most powerful and prominent creatures in High School DxD.

Summary
Dragons are creatures that represent power. As such, in all ages, Dragons are admired, respected, and feared by all. The Dragons are the only creatures whom, as a race, did not side with any of the three factions in the Great War, unlike the Youkai, European Monsters, spirits, fairies, and other supernatural races. However, some individual Dragons "did" join one of the Three Factions.

Dragons are beings created from large masses of energy who act freely and selfishly. Despite this, Dragons have an extremely high level of intelligence.

Azazel theorized that the reason dragons are so powerful is their purity of thought that compels them to devote their all to one goal, for the Evil Dragons, it's battle and carnage. He also observed that Dragons live according to their own will.

It is also a known fact that it is a grave mistake to anger a dragon of any level, whether it be a Low-class Dragon or one of the Heavenly Dragons. The reason being Outrage Mode shown when Fafnir displayed power equal to that of Rizevim Livan Lucifer who is a Super Devil. When a dragon is enraged (or someone who possesses a Dragon-type Sacred Gear), one known way to calm them down is to sing them a song as seen when the Oppai Dragon song calmed down Issei.

Currently, almost all of the Dragons of legend are sealed in Sacred Gears, dormant, missing, or dead.

Dragons love hoarding treasure as seen in the case of Tiamat who in the past, had a hoard of treasure to which some of her treasures were borrowed by Ddraig, who ended up losing them. Losing the treasure of a Dragon angers them to where they will relentlessly pursue whoever lost it, as shown by Tiamat, who has been persistently pursuing Ddraig and his possessors for centuries, to make them pay for losing her treasures.

As shown by Ddraig, dragons revert back to being baby dragons if they don't heal properly as a result of using up too much of their powers.

Appearance
Dragons are creatures with reptilian traits. There are two physical types of Dragons, Western Dragons and Eastern Dragons.


 * The Western Dragons are lizard-like creature that stands on four legs, leathery or bat-like wings growing from their backs, and a long, muscular tail.


 * The Eastern Dragons are typically portrayed as serpentine creatures that have long, slim bodies with four legs, and without wings.

Various Dragons come in different colors, from red (Flame Dragon or Ddraig) to white (Albion) to blue (Tiamat or Sprite Dragon).

Classes
The Dragons are divided into many different classes. There are the normal Dragons, the Dragon Kings which are above the normal Dragons, the Heavenly Dragons which are above the Dragon Kings, and the True Dragon and Dragon God, the highest class of Dragons.

True Dragon
The True Dragon (真龍 Shinryū) is a class that solely belongs to Great Red, the Apocalypse Dragon and the True Red Dragon God Emperor who is known as the "Dragon of Dragons (D×D)". It is the title given to Great Red as the most powerful of Dragons. While Great Red is the only Dragon that belongs to this sub-class, in Volume 12, it is said that Issei could be thought of as a small True Dragon because of having his new body made from Great Red's flesh.

Dragon God
The Dragon God (龍神 Ryūshin) is a class that belongs to Ophis, the Ouroboros Dragon and founder of the Khaos Brigade, and Lilith, the spawn of Ophis.

Two Heavenly Dragons
The Two Heavenly Dragons (二天龍 Nitenryū) are Dragons with powers that can kill both Gods and Satans, and are considered to be one of the highest class of Dragons. The two Heavenly Dragons are the Red Dragon Emperor, Ddraig, and the White Dragon Emperor, Albion.

In the past, the two Heavenly Dragons fought a fierce battle, which was interrupted by the Angels, Devils, and Fallen Angels who were at war during the time. In anger, both Dragons attacked the leaders of the Three Factions, which led to their bodies being destroyed and their souls being sealed into two separate Sacred Gears.

Currently, both of the Heavenly Dragons are sealed within two separate Sacred Gears: Boosted Gear and Divine Dividing.

Five Great Dragon Kings
The Five Great Dragon Kings (五大龍王 Godai Ryūō) are a group of five (previously six) unique Dragons with high destructive powers, rivaling those of Ultimate-Class Devils or even the Four Great Satans. The Five Dragon Kings are Tiamat, Yu-Long, Vritra, Midgardsormr, and Fafnir. Tannin was also one of the Dragon Kings before leaving and joining the Devils.

It is unknown how a Dragon reaches this class, as the other classes appear based on the Dragon's specific type, while the Dragon Kings are of different types and factions.

High-level Dragons
High-level Dragons: A Dragon class that belongs to normal Dragons. A total of four have appeared within the series.

Low-level Dragons
Low-level Dragons: A Dragon class that belongs to normal Dragons. The only Dragon that has been revealed that belongs to this class is the Earth Dragon.
 * The dinosaur that appeared in the short story A Tokusatsu Devil is an example of an Earth Dragon.

Evil Dragons
Another class of Dragon that is first introduced in Volume 14. The Evil Dragons (邪龍 Jaryū) are known to be more powerful than the Five Dragon Kings while the most powerful Evil Dragon in existence, Crom Cruach, is said to be as strong as a Heavenly Dragon. The Evil Dragons are stated to be the most vicious and brutal of all Dragons, all being dangerous battle maniacs that want to destroy everything including themselves. All Evil Dragons were considered as extinct before the beginning of the series. They are considered as "broken Dragons" and are feared by all the factions of the world due to their immense power and extremely savage brutality. Evil Dragons are considered nearly impossible to control as only Evil Gods were able to control them in the past. Evil Dragons can revive themselves naturally if a part of their soul remains. This process, however, consumes a large amount of time.

The Dragons of this class include:

Technically, Vritra is considered to be in this category as well, but he pales in comparison to their iniquity. Among the Evil Dragons, the ones that were the most brutal and stood at the top were:

Currently, all Evil Dragons were revived by Qlippoth of the Khaos Brigade. Out of the seven named Evil Dragons, Crom Cruach defected from Qlippoth, Aži Dahāka and Apophis betrayed Rizevim, Grendel and Ladon were both sealed after their defeat, Niðhöggr was defeated while Yamata no Orochi, Apophis, Aži Dahāka, and Niðhöggr are the only Evil Dragons who died in battle. In Volume 16, Rizevim reveals that with the help of the Sephiroth Graal, he could mass-produce Evil Dragons, using it on the Vampires that already modified themselves using the Holy Grail. The mass-produced Evil Dragons are said to have at least the strength above a Mid-class Devil. Four of these dragons defected and formed a contract with Asia Argento after seeing Fafnir's impromptu cooking show in Volume 17.

Asia named the four:
 * Anselmus
 * Cyril
 * Gregorios
 * Simeon

Dragon Children
Are a group of Dragons who are children of the higher-class of Dragons. So far Tannin, the former Dragon King is known to have three sons.

Other Dragons
There are several Dragons that do not have proper classes due to being a former Dragon or a Dragon that has been forbidden. The two Dragons that belong to this category are Tannin (former Dragon King) and Samael (a Fallen Angel that was turned into a Dragon and sealed). Issei Hyoudou, a humanoid Dragon, could also be considered as a Dragon of this class, as his body is made from the Great Red's flesh through Ophis' powers. This, along with the Boosted Gear, places Issei as a Dragon under the Dragon God, True Dragon, and Heavenly Dragon classes but at the same time, he is not.

Powers and Abilities
The abilities of a Dragon differ between classes, their specific races, and in some cases, the specific Dragon. All of them have demonstrated the power of flight and their own elemental breath weapon (either fire, ice, or lightning).

A frequently seen trait amongst the higher classes of Dragons is the ability to change their appearance to varying degrees. This trait ranges from changing their size (Tannin) to completely changing their outward appearance (Yu-Long, Crom Cruach, Ophis, Tiamat, Bova Tannin, and Alivian).

It has been stated (and shown by Issei) that Dragons draw strong allies and enemies to them.

Unlike other races that have long lifespans, all Dragons have a limitless lifespan, as they do not age after reaching maturity and will only die if they are killed. Dragons (and by extension Dragon-possessors) are immune to poisonous mist created from Youjutsu, which is said to be able to weakened even higher ranking Devils and spirits.

Outrage: Stated in Volume 18, all dragons seem to have the ability to enter an empowered state of sorts when they are angered. In this state, physical abilities increase significantly. When Fafnir entered this state, his power was enough that he was able to knock Lilith to the side and bite off one of Rizevim Livan Lucifer's arms. In the Outrage state, dragons will relentlessly pursue their enemies. Ddraig and Albion also entered Outrage mode back in the Great War and lashed out at the leaders of the Three Factions for interrupting their fight.

Weakness
Despite dragons being considered as masses of energy, a common weakness for dragons are swords imbued with dragon-slaying abilities such as the Holy Sword Ascalon and the Demonic Emperor Sword Gram. Dragons whom have gained a resistance to these Dragon Slayers by either using the Sephiroth Graal; or through intense training as seen with Crom Cruach who defended against an attack from Issei's Crimson Blaster + Ascalon.

So far, the most dangerous weapon against dragons is the deadly poison of the Dragon-Eater, Samael, which not even immensely powerful Dragon Gods such as Ophis and Great Red can remain unaffected by; this poison destroyed Issei's body.

Dragon Gate
The Dragon Gate is a magic circle exclusive to the Dragons. The Dragon Gate allows them to summon another Dragon. While the Dragon Gate insignia can be drawn by someone else, it will only respond when there is a Dragon nearby.

The Dragon Gate insignia is positioned after the Five Dragon Kings, Tannin, the Two Heavenly Dragons, and Grendel. Each of which is represented on the magic circle by a different color:

Despite so, there appear to be other methods to use the Dragon Gate; in Volume 9, the Hero Faction intended to use a brainwashed Yasaka and the spiritual energy from Kyoto to replace the use of the Dragons to open the Dragon Gate.

Trivia

 * There is a race of Dragons who require a special fruit, called the Dragon Apple, to survive. All of the Dragon Apples on Earth have been destroyed due to climate changes, with the ones growing in the Underworld all existing within Tannin's territory.
 * The Dragon Apple was the main reason for Tannin to become a Devil.
 * The Dragons have a disease called the Dragon Flu.
 * Dragon Flu can also be caught by the users of Dragon-type Sacred Gears.
 * Male Dragons take likings to females of other races while hating other males.
 * This is, in fact, the reason why Rassei attacked both Issei and Kiba.
 * Before the introduction of Ophis, the Heavenly Dragons were stated to be the highest class of Dragon.
 * In the 2nd season of the anime, Ddraig called himself and Albion the Twin Sky Dragons, but this is corrected in season 3.
 * Both sub-species Balance Breakers of Blade Blacksmith are Dragon related.
 * Dragons love bananas as shown by Fafnir, Ophis and Crom Cruach.
 * Zmey is bad pronunciation of slavic dragon name "Żmij", which means "viper."