Molydei (singular molydeus) are the jailors of the Abyss, charged with hunting down and incarcerating or killing those who would challenge the established order. This seems rather contradictory given the chaotic nature of the realm itself, which is why the sending of a molydeus is considered an invitation into the ranks of powerful demons. Defeating it allows the target to be recognized as a significant power in the Abyss, and perpetuates the theme of constant change so prevalent in the Infinite Layers. They stand large in height and look like a jackal with a massive axe but they have a serpent that extends out of its neck.
When Tharizdun discovered the shard of utter evil and buried it in the elemental chaos, he charged seven angels with the protection of his treasure. The celestial beings were naturally, obedient, to the wishes of the god, but were unsure if they were doing what they should in listening to the scheming Deity. This left them frustrated and angry. Proximity to the shard caused their forms to violently wrench apart, turning them into the powerful two-headed demons known as the Molydeus.
A Molydeus is typically found alone or with only a small entourage of lesser demons typically mariliths, which the ex-angels enjoy working with. A Molydeus might take Balors, kluirichirs, or other powerful demons, or it might be the enforcer of a demon lord. Molydeus rarely last long on the job however, and typically leave their posts violently.
Molydrus is bound to it’s battle-axe, a tool containing the raw light of creation from when the demon was an angel. If seperated from it’s weapon, the demon will become mad with rage until the axe is recovered or the molydeus can make a new. If a Molydeus is slain, its weapon dissolves in to a puddle of ichor.