The Lieutenant of the Nothing
A legendary creature, possibly a leader of a group of brain symbionts. She might live on a leaf of a giant metaphorical tree representing all order in the multi-universe, with her leaf being the closest part of the tree to the abyss that is the ultimate Nothing, or that could be a complete misunderstanding.
The Lieutenant of the Nothing is almost certainly concerned with uncanniness, being the self-grounding of our openness (to the intelligibility of things) in its own finitude. This incomprehensibility of our own finitude is part of being mortal, and helps to define this state. The study of finitude or mortality, and the way it undermines its own intelligibility in a non-paradoxical, but ultimately self-defeating manner is her sphere of research and power. Thus, anxiety, absurdity, and particularly uncanniness, are some of her more powerful aspects. A related interest is creatures that consume themselves as part of their existence, like the male Angler Fish and the Phoenix (but not the eternal/infinite self-consuming Ouroboros). Her uncanny minions exist as unique individuals only in so far as they copy other individuals, and are immortal (infinite) only through lacking enough of a self to ensure continuity of identity between mortal (finite) hosts; they thus lack uncanniness, except that shared by their hosts. They allow her to capture and analyse non-undermining fragments of mortality.
As a visual analogy, Escher pictures can be seen to contradict themselves, and any single global consistent interpretation of such a picture will lead to its complete disintegration, but without localised consistent interpretations, there is nothing to see. Thus that which gives meaning also undermines any possible coherence and prevents the image's comprehension except in fleeting glimpses. The Lieutenant studies mortal (or finite, including many 'immortal') beings as we might study such a picture, or perhaps as we might set one alight to watch it melting slowly as its contradictory dimensions merge and run together into a new synthesis, or slurry.
The Lieutenant also has a great sense of humour (as Nothing amuses her), although she is not particularly good with crowds. She may be at war with some or all Demon Spiders. She is mentioned, but does not appear, in Much Ado About Nothing.