Armed Brain Army Volt
Believing most of humanity to be inferior, Armed Brain Army Volt is based on the orbiting space station Zuno Base with its officers using a triangular shuttle to journey between it and Earth. Though it appeared Volt's goal was to create the ideal world for superior geniuses and exterminate those with "inferior minds", it's true agenda is to complete the Giga Brain Wave so Bias can achieve immortality while subjugating the human race via mind control.

Great Professor Bias Leader of Volt
A super genius scientist whose appearance belies his actual age, well versed in all knowledge and worshiped as a god by his officers. Bias' intellect prevents him from brutally punishing or berating his officers for their failures; he believes they should recognize and learn from their shame. In reality, Bias was originally human until he devised a means to cheat death by absorbing a mind-controlling thought pattern-based energy called "Giga Brain Wave". But as twelve minds with an IQ of 1,000 each is needed, Bias tricks eleven followers under him to be educated until achieving the ideal IQ. From there, Bias extract the achievers' brains and places them in the Brain Room to set up the Giga Brain Wave. Hiding this from his current followers so he can complete the Giga Brain Wave, Bias took extremes by ordering the execution of Miku Kitamura, a girl from 2003, and then Go, who unknowingly witnessed Bias' previous absorbing of an incomplete Giga Brain Wave. When the effects of begin to waver, Bias attempts to use his incomplete Giga Brain Wave to have Tetsuya destroy the Grand Tortoise for him before it backfired and aged him before he managed to regain his youthful appearance. Soon after, once Kemp reaches the IQ of 1,000, Bias uses Kemp's brain to complete the Giga Brain Wave and becomes a child as a result of absorbing the energy. However, Kemp's spirit rallies the ghosts of Bias' previous victims to take their revenge, causing Bias to revert to his true aged self. He dies in a wizened state aboard the exploding Brain Base with Gash, while hearing the voices of his former officers.

Doctor Kemp / Beauty Beast Kemp (1-35)
Fearbeast Kempu (36-46)

He was formerly known as Kenji Tsukigata, Yusuke's former friend at Academia whose dream was to develop biotechnological means to make humans immune to any disease. However, Kenji became egotistical and power hungry after taking the test Bias sent to him, killing Takuji and Mari while leaving to join Volt. Becoming Bias's top pupil, having an unwavering faith in the professor, Kemp's overconfidence and vanity reflected in his monstrous form of Beauty Beast Kemp, able to execute moves like Beautiful Eye and Beautiful Rainbow. While in human form, he uses the Slit Cutter as a weapon. Wanting to power his Beauty Beast form, Kemp creates Gore Zuno to synthesize his ß ZO Negative blood type before finding Mai, a young woman who saved his life after he suffered blood loss from a lab explosion. After deciding not to take her blood and the events on October 22, Bias is forced to discard his pride and undergo a risky operation to modify himself into a more powerful being. Though Megumi's interference caused him regress to his teenage self with no memory of being in Earth Academia and after, Kemp regains his memories upon remembering his low grade and completes his transformation into Fear Beast Kemp. In his new form, Kemp can use his Kemp Tentacles and execute attacks such as Kemp Demon Flare. He managed to obtain the IQ of 1,000, only to be betrayed by Bias who takes brain away. As a result, Kemp's body becomes the mindless Fear Beast Zuno before being destroyed by Super Live Robo. However, bodiless, Kemp's mind is able to muster enough strength to rob Bias of his newfound youth in the finale. In GaoRanger VS. Super Sentai Yusuke is found visiting his grave.

Doctor Mazenda (1-37)
Machine Mazenda (38-47)
Robo Mazenda (47)

She was formerly known as Rui Senda, a haughty woman who was Megumi's rival at the Academia and broke Yusuke's heart. Rui reconstructs herself as a cyborg to reflect her coldness and her desire to preserve her beauty, with concealed weapons within her robotic body like the Arm Gun, Elbow Gun and Finger Gun. However, Mazenda's subconsciously expresses her regret in discarding her love and kindness which manifests in her attack pattern. Eventually, since the Miku incident, Mazenda begins to doubt Bias before she upgrades herself into Machine Mazenda. In her new state, 90% of Mazenda's body is fully mechanized with new built-in weapons like the Five-Finger Gun, Arm Bazooka, Elbow Gun Double Hit, and Crouch Knee Missile. However, upon learning the truth behind Bias's goals, Mazenda removed all organic traces of her being and became Robo Mazenda to keep Bias from taking her brain. She dies after regaining some of her former humanity. In GaoRanger VS. Super Sentai Yusuke is found visiting her grave.

Doctor Obler (1-21)
He was formerly known as Go Omura, Jou's one-time friend at Academy Island. Go is a childhood prodigy who was forced by his mother Masako to study with no time to play with other children. Struggling to meet everybody's expectations, Go is brought into Volt by Bias out of pity and unknowingly witnessed Bias in his Brain Room. Using Volt's research with his inferiority complex as a motivation, Obler turns himself into a completely inhuman monster; in this state, he uses a battle axe as his weapon. During the failed Benyo Zuno experiment, Obler suddenly regresses to Go; although Guildos returns him to his monstrous form, he is expelled from Volt for his weakness as he reverted again. Stealing Guildos's cross-sword, Go returns to Earth and refuge at his childhood home to perfect his Obler form, destroy the Livemen, and win back Bias' praise. But he is captured by the other Earth-based Volt scientists and used in the creation of the Obler Zuno. When the clone attempts to kill his mother, Obler takes the hit meant from her, reverting to an exhausted, nearly comatose Go. Months after of rehabilitation, Go regains his memories when he was unknowingly used in Kemp's experiment with Tomei Zuno. Soon after, as the young man was a witness to his dark secret, Bias orders his forces to find Go and kill him as Jou manages to get him to safety. Though guilt-ridden by his actions against him and the others, Go as he reveals what he knew about Bias before he went into hiding. Go later finds religion and tries to help the Livemen in hopes of saving Rui and Kenji. Though attempting to protect Mazenda from Gash, Go is unable to save her in the end as he returns to his normal life again.

Doctor Ashura (12-46) and the Shurer Three (14-46)
He was formerly known as Arashi Busujima, a tough-as-nails underworld figure and gang leader with a poor education who bears a grudge against the Science Academia and those smarter than he is. When one of his men is converted into an Apeman by Hihi Zuno, Arashi tracks down the Zuno Beast and uses him to commit crimes before Yusuke battles Arashi in a fist fight prior to Obler's interference. Impressed with Arashi, Bias accelerates his intelligence to the point that he built a chamber that modifies him into his current form. Other than his new found genius and brute strength, Ashura uses the attacks "Demon Kick", "Break Ashura", "Ashura Reverse Attack", and "Cut Ashura". After his initial lost to the Livemen, Ashura remodified himself to execute "Cyber Bunshin" to generate the Shurer Three with whom he executes the "Blood Shed Attack." He is targeted by Bias when he used the Hacker Zuno to uncover suspicious articles regarding Bias' secret. Soon afterward, Bias decides that Ashura is a hopeless candidate and strips him of his super-intelligence. Back to being Arashi, he ends up being befriended by the Liveman and Go before strapping himself with dynamite to makes a suicide run on Battle Zuno. He has a soft spot for women and has sided with Mazenda.

Guardnoid Gash
Bias's robot bodyguard, a relentless machine who knowledge of firearms with use his Video Eye to locate targets. Gash is also the only member of Volt who knows Bias's true plans. Though normally deployed to fire Giga Phantom enlargement bazooka and create Zuno Beasts, Gash is also sent to carry out missions like stealing the Metaforce Jewel from the robot Jou befriended. Gash eventually dies with Bias inside the Brain Base after losing his right forearm to Yusuke.

Guildian Guildos
A robot secretly built by Bias to spur his scientists to break their limitations, believing himself to be an alien intelligence from the planet Guildo. Eventually, becoming prideful from the false memories their creator installed into him, Guildos begins to question why he and Butchy should even follow Bias as he created the Zuno Beast Guild Zuno to prove himself superior to Bias. However, after overexerting his energy to repeatedly revive Guildo Zuno, Guildos malfunctions while realizing his true nature. In a state of shock that his entire life was a lie, Guildos trips and falls to his death.

Chibuchian Butchy
An orange ape-like robot secretly built by Bias to spur on Kemp et al. Like Guildos, he was made to have others believe he was an alien intelligence from the planet Chibuchi. Jocular, likes roller skating and music (he claims to be a karaoke expert). His attacks include expanding the size of his hands to execute his Butchy Punch move. After learning the truth behind Guildos and himself, along with their purpose, Butchy is forced to continue serving Bias. However, while forcefully enacting his Rampaging Destruction scheme, Butchy's tears are noticed by Megumi. Despite Ashura's tough love, Butchy is stopped from further destruction by Megumi offering her friendship. His acceptance results with Butchy labeled a dunce and targeted for execution. Though Megumi tries to save him, Bias activates the self-destruct within Butchy as he pushes Megumi away before explodes.

The green-skinned android soldiers with mohawk 'haircuts'. They are very difficult to defeat, as their head and limbs operate independently when dismembered. Mazenda later develop a variants of Jinmers called Dummymen that can assume human forms. In episode 13, a Dummyman who calls himself Tanaka defects from Volt and assists the Livemen after he falls in love with Colon before sacrificing himself to save her.