The user has a nervous-system outside their body, which makes them immune to pain. The immune system, however, is still defenseless, and if it is harmed the user will feel it. Basically, the system has a connection, a link to its possessor and may even have a life of its own, as well as locomotion.
- While the user and the system are connected, they must protect it since harming it is the only thing dangerous to the user. If the user is attacked, no harm will be felt by any of the two.
- Fredrika (Hitsugi no Chaika)
- BUER (Koukaku no Pandora)
- Fantomex (X-men); has birthed his nervous-system, which then acquired a life of its own and is now called EVA.