Mister Kindly is a shadow daemon, who accompanies Darkin Mia Corvere, and devours her fear. He saved her life as a child, and claims to know very little about his true nature, though he's been known to lie from time to time. He is made from a piece of Anais, the son of Niah.
He wears the shape of a black cat, though he is nothing close to a cat at all. He was described in Nevernight as paper-thin and semi-translucent, "thin as old vellum... a shape cut from a ribbon of darkness...". His voice, "the murmur of satin sheets on cold skin..." and "the kiss of velvet on a babe's skin."
Part in the Chronicle
Mister Kindly's first appearance is at the execution of Mia's father. The girl's rage caused the shadows of the piazza themselves to shiver as she unwittingly called upon them, the beginning of the manifestation of her Darkin abilities. And during this episode, the daemon felt, and answered, her call.
He did not immediately make his presence known. Instead, he chose to remain lurking in her shadow, watching over her throughout her familia's rapid downfall. But, just when the girl was about to be executed, the daemon finally revealed himself to her, and delivered Mia her mother's gravebone dagger, giving her the chance to overpower her captors and escape into the slums of Godsgrave. Once out of immediate danger, the daemon revealed himself to her, and Mia gave the shadowcat his name.
He has remained by her side ever since.