Tattoo

A tattoo is a pattern of nanocels, injected below the skin. These form a kind of advanced cellular automaton, whose 'programming' is a part of their aesthetic design.

Because low-level tattoo design is so difficult, most modern tattoos are formed from smaller components, mostly those developed by Kairo and the Arts Cabal.

Blood magic is based on similar principles, but which is not so obvious. Therefore it is considered "wrong" by the Cabal, who are devoted to stamping it out.