Possession

Possession was a magic ability where the user could inhabit and influence another being or object. Commonly employed by demons, the ability was specific to only select high-level magical techniques utilized by mages.

Mechanics
Possession involved the user inhabiting a being or object as a vessel, allowing them to influence or manipulate that object to a certain extent. When possessing a living being like a human, the user could take full possession of the body, controlling it as if it was the possessor's own by suppressing the possessed's consciousness; while fully possessing the body, the user also had access to the host's magical power and abilities. The possessor and possessed could communicate telepathically as well.

In the case of demonic possession, the demon could additionally influence the host's behavior by rooting itself in the being's mind, though limited to only possessing humans of the Third Period with vulnerabilities or insecurities in their personalities corresponding to the demon's respective sin. Demons were also able to possess humans through doubles they created as extensions of their own beings. Likewise, a demon could forge a contract with its host through possession, as well grant the host access to its powers.

Despite the inherent ability to inhabit a body or object, possession had a number of weaknesses. While possessing a body or object, the user was forced to remain within the vessel until either the possessor chose to relinquish the possession or the vessel was destroyed or killed. In the case of demons using doubles, the vessel containing their true bodies could be sealed or destroyed, causing the doubles to be cut off from their source of power and eventually vanish, also relinquishing possession as a result.

A possession could also be exorcised to forcibly remove the possessor from a host. Despite this, demonic possession could render exorcisms ineffective if too deeply rooted in the being's mind, though the effects could be reversed with the Clockwork Secret Art. Because demonic possession also involved rooting the demon into the host's mind, the demon could be also be affected. Outside of demons, possession was limited to humans able to perform high-level magical techniques like the Swap Technique or borrowing a demon's power.

Users

 * Demon of Lust
 * Demon of Gluttony
 * Demon of Pride
 * Demon of Sloth
 * Demon of Envy
 * Demon of Greed
 * Demon of Wrath
 * Adam Moonlit
 * Irina Clockworker
 * Banica Conchita
 * Elluka Clockworker
 * Gretel

Conceptualization and Origin

 * demonic possession is common in many religions and media, wherein a demon or other malevolent entity takes control of a person's body.