Abyss

Abyss (アビス Abisu) are monstrous creatures that originate from the Ruins and are hostile to humans.

Description
Abyss are mysterious beasts that posses strength and special abilities that differentiate them from normal animals. The average Abyss is several times stronger than a Drag-Knight. They indiscriminately attack humans and animals on sight. Abyss can be controlled by the sounds of a special instrument called a horn flute.

The Ragnarok are eight special Abyss of incredible power. Unlike normal Abyss, each one is a unique existence (though some resemble common types of Abyss, e.g. Poseidon resembles a larger Kraken). Ragnarok cannot be controlled by normal horn flutes. Yggdrasil can be controlled by the unique Origin Variety horn flute, while Ragnarok in general can be controlled by the Moon.

It is eventually revealed that the Abyss were originally created as living weapons by the imperial family of the Holy Arcadia Empire. Normal Abyss were used against rebels, criminals and external enemies, while Ragnarok were used as guards for the Ruins. Angels, a special type of Abyss, were used against the Empire's own citizens, devouring them to obtain their life energy (a necessary ingredient in Elixir).

History
During the time of the Holy Arcadia Empire, its rulers the Lords created the Abyss to serve them.

The Abyss began to appear from the Ruins ten years prior to the present of the series. To defend against them, the majority of nations placed fortresses and barriers near the Ruins and stationed Drag-Knights nearby.

Types of Abyss

 * Angel
 * Chaff Slime
 * Chimera
 * Diabolos
 * Gargoyle
 * Golem
 * Haiit
 * Kraken
 * Phantom
 * Ragnarok
 * Deus ex Machina
 * Fenrir
 * Iblis
 * Metatron
 * Phoenix
 * Poseidon
 * Sacred Eclipse
 * Yggdrasil
 * Shadow
 * Slime