Lemme get you up to speed. Ever since Udon did that DS/SF crossover, they've been releasing one-shots that continue the story. The main crux of the plot is the Shadow Soul (ya know, the hidden fighter in Vampire Savior) possesses/merges/whatever with Jedah, which for some reason causes him to become his Midnight Bliss form.

So BB Hood gets a bunch of Darkstalkers and Street Fighters characters together to stop him. Her. I didn't read it, and I can't find it anywhere online.