They are 'weapons' created by the god of the future, Orntorra, for the purpose of destroying the world and the identities of the guardian beasts that roam in the labyrinths of Bantorra Library.
The conditions for invocation of these beasts are when:
- a Good Person dies in despair.
- a Good Person has cursed the very life that he/she has lived.
- a Good Person doubts his/her very existence in a negative way.
When these conditions are met and the Good Person becomes the master of the beasts; in which he/she becomes the Soul of Destruction, the beasts are invoked to destroy the world.
The beasts in hierarchy are:
- 5th Hierarchy - Cavalry, Needle-haired Wolf, Leno snakes, Rhino, Spitting Bronze Bird.
- 4th Hierarchy - Elephant Soldier, Blade-haired Lion, Fire-Eating Bird.
- 3rd Hierarchy - Spear Fighter, Iron Evil Rat.
- 2nd Hierarchy - Devil Snake, Starved Crying Mantis, Military-Rupture Tortoise
Notably from the illustrations and the anime:
- The Needle-haired Wolf appears in a silver wolf form and can stand and move on its hind legs. It also wears a gold band on its thigh and earrings too.
- The Rhino appears like a rhino form but is a little over reformed from a real one; with larger arms. It wears a gold band on its nasal-horn and is able to stand and move with its hind legs too.
- The Elephant soldier appears maroon-coloured with six legs and wears an earring on its ear. It has two pairs of eyes.
- The Blade-haired Lion has a third eye on its forehead and appears with long, grey mane and black fur. It wears some form of armour on its body and has a gold necklace that is visible below its neck. It also appears to have a gold armband as well. It is able to stand and move with its hind legs .
- The Iron Evil Rat appears white, has red eyes and long front teeth.
- The Starved Crying Mantis appears like a green praying mantis.
- The Military-rupture Tortoise appears as a green tortoise with a black shell and long bushy tail.
- The Devil Snake appears dark-coloured and in numbers. They have a few pairs of eyes.
Source:Wikipedia JP + Bantorra.com