In 1993 japan Shadow was a member of the Black Orchid Corps. She had a hybrid martial art mixing jujutsu and ninjutsu called taijutsu, and also has a master of invisibility.
She was the highest-ranking assassin in the organization, and never really as to many questions about her career until she discovered what would happen to her if she ever failed an assignment, another assassin would come after her.
Shadow being paranoid about that discovered information, the corporation arranged for her to be pushed off from the 101st floor of the Black Orchid building.
When Shadow was able to return, She prevented herself from being pushed off the building. She came to the realization that she was set up by the corporation. Shadow went to the police to be placed in protective custody and she testified in court on Black Orchid Corporation's wrongdoings.
- As well as appearing in Eternal Champions, Shadow starred in her own Mega Drive spin-off game X-Perts (1996).
- Shadow was one of the primary characters in Sonic the Comic's Eternal Champions stories.
- She received an entirely new costume (and sprites) in Challenge from the Dark Side.