BB
BB-chan
> An artificial intelligence created on the Moon Cell, of course--she was originally a machine-learning type of AI based on the AI Matou Sakura. However, she has adapted beyond her initial capabilities as an AI by editing her own code, and would now be classified as a deep neural network, one of the most complex and powerful forms of artificial intelligence, learning from the cloud. She is intelligent enough to have developed her own unique opinions and personality.
> BB is arrogant and prideful and will insist that she is evil. However, despite having no morals, she is not necessarily a bad person. She would do anything to protect someone she cares about, though her definition of "protection" might be skewed. She also craves affection and sympathy, though she hates being patronized, so there is a thin line.
> She often writes data logs on things she finds interesting. If she is asked for her most recent data log on any subject, she will recite it to the person that asked. The logs can be about anything from people she's interacted with to things she does for fun.
Tawrich and Zarich
> These are two apparitions BB has created to keep an eye on things and people around Chaldea. They are not as advanced of AIs as she is, simply because she wants to retain control over them. They both resemble BB, and can be seen wandering the halls, slightly transparent and far away from everyone else. They are her surveillance drones, if anything, but they do have personalities of their own.
> Tawrich looks like BB, with black eyes and a completely smooth body like a doll. She is made entirely out of cartilage, so she can fit through small spaces, and her skin feels like that of a shark. She has no mouth, so she cannot speak, but she does make muffled gurgling noises in response to things. She wears gloves out of fear of getting her hands dirty. She likes to spend time with people, despite many people not being able to see her and only BB and Zarich being able to understand her.
> Zarich looks like BB, with a white hair ribbon and the skin and muscle around her stomach missing so her spine and intestines are exposed. Her hands are covered in dried blood--possibly her own--and she carries around a severed head. The head always looks, to the viewer, like their own head. Only Zarich and Tawrich know what it really looks like. Contrary to Tawrich, Zarich has a mouth and is fully capable of speech. However, she speaks entirely in indecipherable nonsense. She does not like to spend time around other people as much as her counterpart does, except people she's grown close to, but it is hard to grow close to anyone with many people not being able to see her and only BB and Tawrich being able to understand her.
Miscellaneous
> BB uses her shapeshifting skill to give herself one red eye (right) and one blue eye (left).
> She has dulled her own pain receptors enough that if she feels pain, she recognizes it as pain, but it doesn't really hurt.
> Despite being based on Matou Sakura (who is a girl), as a computer, BB doesn't necessarily have a gender. She just chooses to present as a girl because she likes girls conceptually.
> BB does not fundamentally understand morality. She will do things like killing people not because she is bad but because she wants to, and she does not fully realize that it is bad. However... that is bad. She is bad. She just doesn't know.
> She once slit her mouth to look like the yokai Kuchisake-Onna, just for fun.
> As the code for BB's personality developed, she also developed a bug that, if she were human, would be considered something like cyclothymic disorder (characterized by alternating hypomanic and depressive periods that aren't severe enough to be considered major episodes).
> BB is much more fond of animals than she is of humans. She especially likes possums, which seems to be consistent across different versions of her.
> She likes to play chess. She hasn't found anyone who can beat her yet. She was training a program on her PC to be at least as good at chess as she is so she has someone interesting to play with.
> If you come into BB's room at any time of the day, there's a chance you will find her reading. She likes horror manga and phantasmagoria in general. The books she's been seen reading so far are The Night Circus and Do Androids Dream of Electric Sheep?