Plume of Dusk

Plume of Dusks are crystalline substances named after their appearance which, although never shown visually, are described to be thin and both platelike and circuit-like. Plume of Dusks are also described as vital, "similar to a living thing, yet different" as well as said to "exist in a state between mind and matter, mass and information", a description harkening back to that of the Velvet Room.

They are primarily used in the cores of the personality modules of the robotic Anti-Shadow Suppression Weapons in order to grant an awareness from which they can summon a Persona. In Persona 4 Arena, it is revealed that earlier models such as those in the twenties and below (such as Unit ) had lesser sized Plume of Dusks while researchers had implanted full-sized ones in later models, most notably Aigis or Labrys.