Gaee

Gaee is the result of experiments. Scientist tried to make a specimen that'd survive in harsh environment, but the results exceeded what they expected. In fact, Gaee is oxygen intolerent, and can only breathe toxic gases and such. No pure air for him. His mask provides him with a constant flow of diverse gases so he doesn't suffocate. He fled the laboratory and now works with the AR as an anesthesist with the medical team.