Aravelle
Sage
Do you know of any book series[es?] including your own that employ this kind of magic? If so, what are the rules? How does the system work? Does it have to be your own body parts, or can it be someone else's? Must it be a willing volunteer or no? I read about this kind in How To Write Science Fiction and Fantasy, by Orson Scott Card. I haven't read a book series yet that employs magic like this, but figured there has to be at least a FEW books out there that do.