One of the Twelve Demons in the DRU.
Aka Manah is the Demon of "Evil Intentions". He's notorious for getting into the minds of his victims and bringing out their darker tendencies.
The Artifact found in Song of the Sea, is thought to be of his origin.
In A Tale of Two Sirens, he "marks" Ashley Martin and starts to appear in her dreams. He attempts to corrupt and take over her body but Ashley is ultimately successful in repeling him.
In Season of the Witch, Sophie uses her magic to "force" Kelly to steal his orb where it was safely locked away in The Vault after the events of Song of the Sea. The orb eventually ends up in the hands of a man named Talbot who dies in the forest, where Ashley finds the orb in A Tale of Two Sirens.