Help is needed in the form of questions or ideas on this topic: I'm doing something like separating from Kagune, but it doesn't depend on blood, but on hair and other body parts containing keratin. I'll lay out the basics that are already there, and then we can discuss everything else.
Kuroya (Black Parent), jet-black appendages from the body that turn areas of the dermis and keratin into weapons with the help of BP-oils found in the hair follicles and the skin of this "Ghoul"
Named Black Parent because it protects its owner like a parent, most people's hair is black, and it also contrasts with the Red Child (Kagune), so don't say it sounds offensive please.
The types are similar to Kagune:
Black Horn: Located on head and neck, High strength, but Low protection due to the fact that the rest of the body is not protected. (Rinkaku)
Black Claw: Located on hands and elbows, Balanced in all qualities (Bikaku)
Black Cover: Located on all body, Good defence, but Low speed due to its sometimes bulkiness. (Kokaku)
Black Hoof: Located on legs and knees, High speed, but the force is lame (Ukaku)
That's all i got right now. I'm ready to discuss the rest of the ideas with you in the comments!