"But I know The Makuta is here now, in these burnt trees, and in the dead soil. All of these things were destroyed by The Makuta, but he never left them. That is how he becomes strong. That is what The Makuta does. He destroys things."
—Matoran Kapura, about Makuta Teridax, Mata Nui Online Game
- Makuta Teridax serves as the Overarching Villain of the entire franchise. A treacherous sociopath who betrayed Mata Nui and plunged him into an unending slumber, Teridax went on to terrorize the island of Mata Nui by unleashing corrupted Rahi and the Bohrok in the Chronicles era to wipe out Matoran civilizations, later using the Piraka as his puppets to enslave and murder the Matoran of Voya Nui in the Ignition and Legends arcs, before betraying his entire race of Makuta to destruction as part of his master plan. In the Glatorian arc, Teridax usurps and banishes Mata Nui, assuming control of the Matoran Universe and beginning to reshape it to his whims, before trying to wipe out Mata Nui's new home of Bara Magna and its billions of inhabitants—including his own armies—just to spite Mata Nui, planning to then move on and conquer all life across all universes, and wipe out any who oppose his reign. Always portrayed as evil as he is brilliant and manipulative, Teridax threatened billions of lives with his villainy, with nearly every major act of horror in the story tying back to Teridax in some way:
- Animated film trilogy (in chronological order): Makuta Teridax schemes to rule the Matoran in Legends of Metru Nui, plunging Metru Nui's leader Turaga Dume into a stasis slumber and assuming control of Metru Nui. Hiring the Dark Hunters Krekka and Nidhiki to hunt and kill Toa, Teridax frames the Toa Metru and orders them eliminated before trapping thousands of Matoran in stasis pods, planning to wipe their memories then awaken them as their savior and ruler. When the Toa interfere, Teridax murders Nidhiki and Krekka to absorb their power and tries to destroy the Toa and dozens of Matoran they are rescuing, killing Turaga Lhikan in the process. Though beaten, Teridax calls to Roodaka and Sidorak in Web of Shadows, having them overrun Metru Nui with Visorak and reduce the island to a barren wasteland, hoping to leave the slumbering Matoran trapped forever. Returning to terrorize the Matoran once more in Mask of Light, Teridax unleashes the Rakshi onto a variety of Matoran cities, ordering them to destroy everything and everyone in their path to retrieve the Mask of Light, and tries to tempt Takua into betraying his best friend to destruction.
- Podcasts and serials: In the Web Original serials, podcasts and story blogs, Makuta Teridax's rise to power and ensuing reign is given insight to its full depravity. When Teridax staged his coup against Mata Nui and the Brotherhood of Makuta, he had any dissenters to his rule hunted down and brutally murdered, mounting their masks on his wall as trophies. Encouraging and endorsing betrayals, mass murders, and horrific experiments in his Brotherhood, Teridax soon enough assumes control of the entire Matoran Universe and enslaves any surviving Makuta before exterminating them all to ensure no threats to his rule. As supreme god of the Matoran, Teridax tortures and corrupts Toa into insanity and villainy, turns one of his former partners into a painting, and begins systematically wiping out thousands of innocent beings as he establishes his godhood.
- Semi-canon tie-in video games: Makuta Teridax first infects the Rahi of Mata Nui in Mata Nui Online, driving the docile creatures mad and siccing them onto Matoran villages, nearly drowning the entirety of Ga-Koro as just one example of the ensuing destruction. Reducing entire forests to scorched ashes and using the naive Akhmou to unleash a plague onto Po-Koro that nearly wipes the whole city out, Teridax corrupts and controls Toa Lewa into enslaving Matoran and working them to near death, all while Lewa is completely aware of the wrongdoing he is carrying out. In BIONICLE: The Game, Teridax unleashes Bohrok and Rahi onto Matoran across Mata Nui, putting hundreds in peril, and in the DS version of BIONICLE Heroes, Teridax captures the Toa Inika and strips them of their masks before using their power to rip Voya Nui apart.
- Makuta Mutran serves the Brotherhood of Makuta for the chance to perform his psychotic experiments unimpeded. Causing trouble even when the Brotherhood was more heroic, Mutran creates Matoran-devouring monstrosities and is known to have unleashed his beasts during the time of a civil war so as to cover up the death and destruction his creations wreak. Once gaining insight into the future and learning of Teridax's plans and the universe-wide destruction it will cause, Mutran doubles his efforts to get into Teridax's good graces and happily joins his revolution against Mata Nui, continuing his horrifying experiments in the process. Once developing the nightmarish Shadow Leeches, parasites that painfully devour all of the good out of their target, Mutran happily obliges Teridax's order to use them on an entire island, and thus rips out the morals of hundreds of Matoran, turning them into the Brotherhood's evil slaves. Wanting nothing more than to torture, experiment, and dissect all around him, what Mutran lacked in power he more than made up for in unbridled scientific sadism.
- The Shadowed One is the cruel head of the Dark Hunters, a shadowy organization of assassins and bounty hunters willing to do anything for profit. Ruling the Dark Hunters with an iron fist, the Shadowed One punishes minor slip-ups with torture and dismemberment, failure with death, and treachery with far worse than either. The Shadowed One uses the Dark Hunters to carry out countless acts of murder, slavery, and kidnapping, and, though many of the Hunters are just psychotic and greedy, some are forced into service by the Shadowed One when he threatens their lives or the lives of their loved ones. With no loyalty or true care to any but himself, the Shadowed One's Dragon lives a constantly tortured existence due to horrifying experiments the Shadowed One performed on him, while the Shadowed One's "closest ally", Ancient, is coldly executed by the Shadowed One to cover up a secret weapon of his own. By the end of the story, the Shadowed One has foregone all form of secrecy and subtlety to instead wage a war against the entire city of Metru Nui, and later attempts to harness the power of a lethal virus to blackmail any civilizations he wants with it. The Shadowed One is regarded as the most dangerous person in the universe alongside Makuta Teridax, and he does nothing to dissuade this proclamation.
- Roodaka is a treacherous manipulator who plays any and all potential allies for fools to get what she wants. With her powers of mutation, Roodaka makes a name for herself in both the Dark Hunters and the Brotherhood of Makuta due to her habit of mutating people into monstrous beasts to cow them into her service. Once becoming the Viceroy to Sidorak, king of the Visorak horde who she eventually betrays and leaves for dead, Roodaka uses her position to aide Teridax in wiping out entire islands of all life and turning any Toa who stand against her into mutated beasts just to mock them. Roodaka's biggest and most wicked plan is to release Teridax from his confinement, fully knowing the countless amounts of death and destruction he will cause, but uncaring as long as it asserts her dominance in the universe. One of the most self-serving villains in the BIONICLE universe, Roodaka truly cared for nothing and nobody besides herself and her own power.
- Pridak, known as "the Shark", was once the self-appointed ruler of the "League of Six Kingdoms", a villainous empire headed by himself and 5 other criminals, together known as the "Barraki". note As the leader of this League, Pridak organized the other Barraki to conquer nearly the entire Matoran Universe, slaughtering all those who aren't enslaved, with Pridak's own minions fairing no better, as he orders an entire battalion massacred simply because 3 of the over 50 soldiers in said battalion took a break. Though severely weakened after being locked away in the underwater prison the Pit, Pridak continues his plans for conquest, as he dismembers fellow Barraki if they question him, sics his pet sharks on Matoran, and forces another to watch as his city is ravaged by Pridak's forces. After escaping the Pit and ditching the other Barraki, Pridak tries to resume his insane plans for conquest, successfully wiping out a small island before being stopped. Pridak was the absolute worst the Barraki had to offer, and gleefully accepted this role in stride.
- Tuyet, a Toa of Water, is a fanatic who is obsessed with imposing her own "order" on the universe. While a nasty being who sadistically murders 3 Matoran to cover up a weapon she found in the "prime" Matoran Universe, it is in the Dark Mirror alternate universe where her evil shines. Having evaded capture for her Matoran serial killing by murdering Toa Lhikan, Tuyet uses the Nui Stone to convince other Toa to join together and create the "Toa Empire", a military ruling body that imposes their version of peace on the Matoran. Any Toa who stood against Tuyet were summarily brainwashed or executed, with the same fate befalling countless Matoran for the pettiest of infractions, with Tuyet ordering the liquidation of an entire tribe of Matoran solely because they have the ability to stand against her; one Matoran was frozen alive for walking too slowly. Along with covering the walls of her base with "trophies" ranging from weapons of fallen opponents to the opponents themselves, turned into living statues and decorations, Tuyet treats the Matoran as animals to be subjugated, going so far as to almost wipe out hundreds of them who rebel, only hesitating because it would leave her with less to lord over. With a final plan of conquering all other universes and turning then into totalitarian society she has created in her own, Tuyet was a terrifying example of a Toa's ability to take their "duty" way too far and become far worse than those monsters they claim to oppose.
- Metus is a slimy, treacherous Agori who sells out the entirety of Bara Magna to the Skrall for his own personal profit. His cowardly nature evident in the past when he ditched an entire group of his people to die to save his own skin, Metus later allies with the Skrall leader Tuma, offering him information on Agori village defenses and selling its defenders into slavery so the Skrall can wipe out the villages and either enslave or kill their inhabitants. After agreeing with Tuma that should anything happen to the Skrall leader Metus will assume command, Metus arranges for Tuma's death before taking control of the Skrall, planning to murder all those who know his true nature before conquering all of Bara Magna from the shadows. Despite his limited powers and abilities, Metus's evil is so wretched and his heart so black that Mata Nui compares his depravity to Makuta Teridax himself.
- Sahmad's Tale: Annona is one of the few villains to surface only after Teridax's defeat, and handily the worst. An ancient, dream-devouring entity, Annona drains entire civilizations of their dreams for empowerment, and the resulting lack of dreams drives the victims insane before they agonizingly die, something Annona drags out as long as possible so as to savor the taste of the dreams. After failing to drive the Great Beings themselves to madness to assert her dominance, Annona replenishes her strength by draining the Iron Tribe's dreams, leading to the annihilation of the Tribe, and later grants all females of the Skrall species with psionic abilities to watch as they wipe out the male Skralls for nothing but her own entertainment. Once awakening from her slumber, Annona enslaves the female Skralls for failing her, turning them into controlled puppets, then attempts to continue her spree of dream-devouring, even attempting to weasel her way out of a fight so as to feed on an entire planet. Treating her victims as nothing but "lunch", Annona was a purely evil monster who stands out as the only purely evil villain the Matoran encounter on Bara Magna.