BB/GO

BB/GO is an Advanced AI salvaged from Kiara Sessyoin's body upon turning Seraphix into a copy of SE.RA.PH. She is a MoonCancer-class Servant.

Background
Upon replicating her body that was obtained in the Moon Cell, Kiara was able to extract BB, Passionlip, and Meltlilith who she had absorbed to obtain that body. After the copy of BB was sent from the Moon Cell, she took to calling herself "BB/GO."