Wrens

The Wrens or, Kinglets in the English subtitles, are former vassals of the deceased monarch of The Valley of the Kings, King Vévrier I. After Vévriers death, the power-hungry vassal Raghan the Clairvoyant questioned the legitimacy of Theodore the heir to the throne. This scandal acted as a catalyst for the other vassals to voice their entitlement which soon escalated into a gruesome feudal war, the consequence of which is that the memory of the Wrens were omitted almost entirely out of all historical records and survived only as myth. The demonic vassals themselves were vanquished one by one by Theodore and 5 elemental magic wielding knights. Dispossessed of their bodies, their souls were exiled into the void between worlds (or Purgatory, in the English dub), but not before Raghan swore to return and cause bloodshed in retaliation.

A decade prior to the start of the animated series, Howard MacKenzie used an occult ritual to contact Gobniu, a Wren who forged a magic cup that can open a gateway to the Valley of the Kings. Instead, the spirit of Raghan was summoned and duped Howard to instead summon the spirits of the Wrens into the bodies of random citizens of Paxtown, among the many victims of this accident was his university friend Charles Vales who became possessed by the Wren, Rizel.

Abilities
Every Wren has a unique superhuman ability. One ability all Wrens share is their connection. According to Rizel, all Wrens are interconnected, so a Wren can feel the presence of another Wren. A Wren heart is considered to be a source of power amongst the Wrens. If a Wren eats the heart of another Wren, they become much stronger than before.

In human form, they preserve the memories and attitudes of their host (career, family)...) and more or less of their physical traits as they change. They all have in common the black sclera and a great capacity for regeneration. The heart is their weak point. In addition, each Wren has specific abilities and powers.

Chorum is said to be the most powerful Wren.

List of Wrens
It is revealed during the series that the one who accidentally released the Wrens is none other than Howard. Fascinated since childhood by the Valley of the Kings and eager to go there, he tried with his friends during a séance of spiritualism to talk to Gobniu, the Wren having created a magic Cup that opens a passage to reach the Valley. Instead of Gobniu, they get in touch with Raghan, the Wren of clairvoyance. Howard's friends, starting to get scared, decided to leave. Only Charles Vales remained with Howard. Raghan manipulates him by telepathically showing him the ritual apparently necessary to make the cup appear. Howard falls into the demon's trap and the ritual, once carried out, releases the Wrens, who disperse in the city of Paxtown. One of them, Rizel, reincarnates in Charles' body.

For the next ten years, Howard and his brother Dave hunted down Wrens to eliminate them. To list the Wrens, they draw up a list of the 31 demons and their hosts, which they update as they eliminate them. Indeed, as Raghan explains to him, Howard being the one who did the ritual, he is the only one who knows the names of the hosts of the Wrens. However, although he knew about it, he did not know which Wren each person was associated with before he saw them use their powers

Faligule

Trivia

 * The French name of the Wrens is Roitelet (alternate spelling Roilet) which translates to Kinglet. In real life both the Wren and the Kinglet are families of birds (the former is Troglodytidae and the latter is Regulidae) originating from the order Passeriformes. In Europe Wren and Kinglet are interchangeable because of these familial connections and similar appearance. The concept of the Wren fighting each other for the throne of the Valley of Kings may have been strongly inspired by an old fable which depicted a competitive event between different bird species over who will be the king of birds. The predatory eagle came the closest to reaching the mountainous destination which determined the king only to be beaten by the much smaller and cunning Kinglet bird.
 * According to Howard MacKenzie in We will dismember you, the remaining Wrens were the most dangerous and Gobniu was one of the most evil.