RIA is the Nightmare counterpart of AIR.
RIA was built by Nightmare Ark. She is exactly the same as AIR, but she is not quite as smart. She is much stronger and much fiercer, but Nightmare Ark built RIA to protect her, instead of to collect information.
RIA is very clever. She is incredibly loyal, but only to Nightmare Ark, and sometimes Nightmare Vira or Nightmare Comatose. But if anyone else tried to command her, she would vaporize them instantly.
RIA looks exactly like AIR, just with black metal and dark gray eyes.
Nightmare Ark- RIA is incredibly loyal to Nightmare Ark.
Invader Ark- RIA wants to help Nightmare Ark destroy Ark.
Nightmare Vira- RIA half-trusts Nightmare Vira and will serve her if Nightmare Ark wants her to.
Nightmare Fury- RIA and Nightmare Fury are okay friends.
Nightmare Comatose- RIA feels the same about Nightmare Comatose as she does about Nightmare Vira.