Satan Egos is the mysterious leader of the Secret Society Egos.
Satan Egos is a black-robed man who sits lotus on a platform high above all of his followers, including his commanders Commander Hedder and Salomé. His identity remains mysterious and is never unrobed. Satan Egos sits behind a spinning pentagon crystal; this crystal is the main means by which the being speaks and likewise is the means he beams his own energy to create his "children" Egos Monsters with his Monster Making Capsule.
Powers and Abilities
Satan Egos possesses mysterious powers, using a combination of science and dark abilities to rule and control over Egos and his followers. His main ability is through the creation of his "children", using his own dark energy beamed from a crystal as well as a massive "Monster-Making Capsule" (a device that resembles a heart or a womb), which can turn anything inside of it, from inanimate objects to actual people, into an Egos Monster. Nearly all of his creations are fully corrupted in mind, body and soul; the only one who may not have been was the Mechanical Doll Monster, which gained a conscious due to interactions with Battle Fever and Masaru Nakahara but still considered itself evil and needed to be destroyed by Battle Fever. Satan Egos also instructs the construction of new devices, most notably the "little brother" robots used alongside his own monsters to further confound Battle Fever in battle.
After the destruction of his Monster-Making Capsule, Satan Egos reveals he can use his own supernatural powers to augment himself and make himself super-powerful.
As leader of Egos, Satan Egos has been stated as the black curtain behind all troubles and problems that have occurred throughout world history. Everything from natural disasters to assassinations to wars have connection to him, generally through his Egos followers or through his "children" monsters that he creates to cause chaos. When General Kurama Tetsuzan catches on to Satan Egos' actions, he creates Battle Fever and the means for managing with the evil overlord, including the development of Battle Fever Robo as a secret weapon for dealing with Satan Egos' secret "robot" project.
All of Satan Egos' actions are performed by his men, including his Monsters, his army of Cutmen and his head general, Commander Hedder. He demands complete loyalty to all of his men and comes up with schemes for causing chaos through the world or takes in other ideas which he gives his permission for performance. However he must be approached for any changes and for the loyalty of his followers; when Hedder brings in American Egos agent Salomé, she must first prove herself to Satan Egos in facing Battle Fever before she is permitted to join in their main task force.
As Battle Fever continue to thwart plan after plan, Satan Egos' plots turn more towards figuring out ways to defeat or even kill the team or discovering their base for its destruction. These maneuvers have lead to two ultimate successes: the removal of Diane Martin after bringing in the dangerous Dracula Monster and the murder of Kensaku Shiraishi in broad daylight. Although both members were replaced ultimately, the danger for Egos remained relevant.
Altough Satan Egos was able to continue to lead and support his organization and all of it's schemes, it is his reliance on Hedder that leads to his downfall. When Hedder decides to go off on his own to defeat Tetsuzan with his own style, Satan Egos permits him, but the move ultimately leads to the commander's death. After Hedder's death, Satan Egos uses his Monster-Making Capsule to turn his former leader into the Hedder Monster, believing that its revival abilities were enough to confound the team and sneak to destroy the base. Yet Tetsuzan once again defeats the commander, freezing him using his robot mynah bird Kyutaro and then having Battle Fever annihilate his remains, eliminating Egos' most reliable leader.
Angered by the defeat of Hedder, Satan Egos begins a final operation to lure Battle Fever to him, using natural disasters and making Salome give them directions to their secret headquarters. Once there, the leader uses the Monster-Making Capsule to capture Battle Fever in order to turn them into an Egos Monster to both help him and eliminate their threat. However the team escape and destroy the capsule in the process, angering Satan Egos to the point that he leaves his base to collapse and grows to a massive size to destroy Japan on his own. Battle Fever face him in Battle Fever Robo, having a hard time even touching his supernatural powers until combining their powers to throw their Denkouken at the black-robed giant. The hit kills Satan Egos instantly, while his death simultaneously destroys all Egos beings still within the world, eliminating any influence he had in the world instantaneously and bringing it to peace.
When ©Na replaces the Super Sentai Series with her own Super ©Na Series, she takes Satan Egos' place as Dark Priestess ©Na in her version of Battle Fever J.
- Satan Egos' personal growth in the final episode is the first time a being grows to a giant size in Sentai (prior to this, all of Egos' threats were merely their little-brother robots). This would become the standard for nearly every Sentai afterwards, with the monsters and other beings personally growing instead of using another means to fight. (the only exceptions being Goggle V, Bioman, Dekaranger and Go-Busters)