Due to the limitations of how much exposition one can fit into a story without it reading like an encyclopedia, a few things got dropped out that would probably appear in my imaginary Director’s Cut version of it. One such part that got cut was a scene in which Vuluora asks Sÿnkura if he knows anything about the Black Bloods, and Sÿnkura’s all like “Dude, shh, don’t talk about them, how did you know that name anyway?”
And the dialogue goes on to explain that the Black Bloods is the name of a criminal organization running the black market of Southport, through violently maintaining a monopoly on all forbidden items. So then in the fight scene, it is implied that these three drug-pushers are members of the Black Bloods, because obviously black hooded cloaks are sinister. By similarity of outfit, one also might be able to deduce that the Emissary of Cain is also a member of the Black Bloods.
But who is this mysterious Lady in charge of them? And what is she doing with a live, captive human? Well, that shall remain a mystery for now.