Evil Science Empire Fiendishdark was an ancient empire that had once scourged the Bay Area with their leader, Lord Sinistercyclops, many years ago. Initially seeking money and profit, Evil Science Empire Fiendishdark's intentions had changed to fulfilling their leader's vengeance against the Rangers and the reconstruction of Evil Science Empire Fiendishdark and domination of the skies.
Long ago, Army General Swordsman Washington, Commander Tina Nelson, Dr. Scorpionwoman, Dr. Iguanaman, Lola, Tara and the Neo-Atom Mayhem Beasts were sealed away in the Fiendishdark Realm by Nguyen Phu Trong, who also imprisoned Grand Marshal Pharaohondo in the Golden Urn of Underworld, with the help of a special type of poison. After Dan and Chris freed Grand Marshal Pharaohondo many years later, the deceptive Egyptian king reunited the six generals of Evil Science Empire Fiendishdark and found out his home realm was collapsing. As a result, he sought vengeance of the Rangers, trapping all of them in the Souls of Fiendishdark Sword.
- Super Sentai counterpart in Dai Sentai Goggle-V.
