"I offer you emptiness."
Basic Physical Characteristics
Cocytos carries the stigmata of her kind heavily, her body little else than a puppet and a tool. Even her most low-intensity incarnations are filled with dust, ash and cinders when damaged or disturbed too violently. Unless she concentrates, even her saliva is composed of a type of blood.
In her mid- to high-level incarnations, her eyes often change the pattern and colour of her irises whenever she blinks, hinting of the many souls her own now brushes against, and who whisper and pull in her mind. If she concentrates, her human self remains at the surface, allowing her to both be more lucid and to allow her eyes to stay the same.
Basic Metaphysical Characteristics
Cocytos is an Avatar of Autumn, a soldier of unmaking, and is closely connected to waning energies and the void. As such she manifests and acts for corruption and destruction. Wheter the destruction is succeeded matters little, but she has a psychological need for it. Just like a human being needs to do human things, such as eat, socialize, express themselves: so must express her own nature.
Her proxy soul is derived of more than one on her home plane, the expression of her self, identity and opinions varying quite often as a result to the crude incorporation of her soul into the structure of her reality. This, however, makes her more sensitive to the collective will and many nuances of both the souls above and beneath her. This is the reason she's rarely lucid, the gods of her worlds leak through into her mind, identity and memories. Her interpretation tend to be rather morbid or negative, as they are filtered through her Autumn-aligned seasonal gate.
Personality
Cocytos is seldom lucid, and often floats within the metaphysical currents of the world she is an expression of as they pass through her mind and soul. There are some incarnations, specifically one which constantly resides within the Namtari Boundless Palace, who are quite close to the human she once was: But most simply containers, guided by her human soul and personality. Different incarnations follows different ideologies in differnet situations depending on what they deem the best way to unmake souls and even entire realities.
Despite Cocytos' rather grim position and life, should one be lucky enough to catch the attention of her human self, she can be quite friendly and considerate. This is however, expressed through aforementioned mind, and she might aswell attempt to unmake your soul out of affection as she might be to try and protect it.