Siesta

The odd one out in the six Shadow Siblings, Siesta was born half-human and resulted out of a genetic experiment that was done without Matron's permission or knowledge. Never really getting to know her siblings, neither when they were alive or became Shadow Spirits, Siesta was put to work within a fighting ring from the day she could wield a knife. Growing up with the expectation that she would be unrivalled on the battlefield, Siesta both failed their expectations and proved herself in an unseen manner. While unable to properly wield Emotion magic herself, she was able to amplify the emotions of her enemies and those who were able to wield that sort of magic herself, to the point of inducing a breakdown in those who came into contact with her when she was in an especially bad mood during combat. Eventually, however, the chameleon grew bored of this lifestyle, and staged a coup. Fleeing at the cost of her tail and some muscle mobility in her left leg, Siesta eventually joined the IRC (that being the Intergalactic Ragnarok Committee), a group focused on helping the suppressed half-humans of each culture out to the best of their abilities. The purpose of this organization was to elevate half-breeds to their own ranks and help them toss off the stigma that came with being half-anything. Currently, this organization is still working to achieve this goal, to mixed results.

Siesta was originally assigned to protect Mikage, given his lineage and unfortunate circumstances (as she met him right after he went temporarily mad from abuse and slaughtered his cruel mother). However, due to the interference of people like Hakune, Reiki, Hikaru and Denkou (Mikage's mentor and friends), she withdrew from Mikage before either of them could get into deep trouble (as mingling with an IRC agent would've meant Mikage would've suffered a lot of legal issues). Despite this, she was very close with Mikage during the 11 years they were together.

Her next and current host is Nova/Mori, a half-Mystic, half-Youkai. Assigned to watch over him because of his intriguing potential (being the offspring of two rivalling species), while they squabble fairly often, they can manage to work together fairly well. As of the current time, Siesta seems content, though she does miss Mikage.

Here's an old reference of Siesta in her Mikage-like form. Her extra limbs match those of her hosts (normally she simply has chameleon features). Her eyes are also fairly odd.