Bio-Nanite Network

These nanites are composed of metal with biological behaviors, allowing them to grow and adapt to their circumstances. Created by dark elven scientists of the Scarlet Sisters, only a handful of organizations have learned how to create or program bio-nanite networks.
  When uncontrolled, they’re essentially harmless; they’ll form into a metal ball and just exist, as far as anyone can tell. They aren’t anything like gray goo. When controlled, they can be incredibly useful.
  Bio-nanite networks are primarily used for mental implants, and are notoriously difficult to hack or alter without the cooperation of their host.
  They can also be used for self-repairing armor or weapons but creating them in sufficient quantities to do so is difficult.