The OverLord is the highest power among the Unknown, and is referred to as the creator of the human race. Long ago, there existed twin entities of the Linto Tribe; one being the embodiment of light while the other was embodiment of darkness. These twin 'brothers' co-existed in harmony for a time, eventually creating our world. However, neither could agree on who would reign over their creation and a battle for control took place. In the end, the Overlord of Darkness triumphed over his brother, the Overlord of Light. But with his dying breath, the Overlord of Light bestowed his essence upon humanity—the power of Agito—with the hopes that, one day, they would evolve beyond his control. But the Overlord of Darkness refused to let this occur, taking it upon himself to personally eliminate the vessels of Agito, creating the Lords to kill all humans who possess the potential to 'evolve' into Agito.
Though he died around the Pleistocene, the Overlord of Darkness left a puzzle that held a model of his very own DNA. Once the puzzle was solved, the Overlord's DNA was reconstructed from scratch. He reformed his physical body, starting off as an infant as he broke out of the containment box and escaped from the O-Parts lab. His birth was witnessed by Sakiko Mikumo, following her after he matured to an eight-year-old boy until she was killed by Anguis Femineus, whom the Overlord punished. Encountering Ryo as he was near death, the Overlord used his power to prolong his life, assuming his adult form as a result. After forced to take his leave after being nearly killed by Gills, the Overlord personally murdered Tomoko Miura, getting arrested and placed in a mental ward after he shut down from the burden of personally killing a human. As a result, the Overlord decided to watch from the sidelines as the Lords committed various supernatural murders on anyone reaching paranormal maturity, though he intervened once to give Agito's Tornador a power-boost.
But the lost of the El of the Sea opened the eyes of the Overlord to the reality Agito and the others had grown too powerful. He wanted to personally remove the Seeds of Agito from the Riders. But with Hikawa's aid, Shoichi dealt a decisive blow to the Overlord that released the Seeds of Agito back to their rightful owners and forced the Overlord to retreat.The Overlord would put his genocide of humanity into action: realigning the constellations of the Zodiac, ultimately killing off all of mankind in bizarre doppelgänger homicides starting with those born under Scorpio. To do this requires tremendous concentration, which would render him vulnerable. To this end, he creates the El of the Wind to be his bodyguard and the El of the Ground to continue killing those reaching paranormal maturity. But the Riders makes one final stand and with the El Lords destroyed, the Overlord attempts to retreat but is mortally wounded by Agito's Shining Rider Kick. But the Overlord survived the fatal attack and has a conversation with Tetsuya Sawaki before he died. Convincing him that while he created mankind, the Overlord didn't truly understand them. Afterwards, he hints that he decides to postpone his plans and wait to see what the future holds for humanity, before vanishing, his true fate is left unknown.
Under the Overlord exists three very powerful Lords, known as the El Lords. They normally reside with their master's body until summoned, possessing the ability of speech.
The strong whale Lord, he uses a forked spear Resentment Du Sanga, along with telekinesis and regeneration. He is responsible for the Akatsuki Incident, "killing" Sawaki when he awakened as the 2nd Agito. The El of Water allowed the others aboard to live until they undergo the evolution to Agito, entering the body of Masumi Seika to ensure they never tell anyone of what had happened. He eventually awakened, using Masumi to kill for him until he found the Overlord who gave him the power needed to leave his host, killing her. Using Orcinus to stall Agito, the El arrived to personally finish the job and kill Shoichi. However Ryo intervened and got Shoichi out of harm's way. The El of Water later encountered G3-X, after sensing Hikawa's zero potential of becoming an Agito himself. The El Lord was eventually defeated by Agito's Burning Bomber, returning to the Overlord's body to recuperate and undergo an evolution of his own. By the time he completed the changes, the Overlord sent the El of the Water after the Agitos. In his new Strengthen Form, the El of the Water possess a the Hateful Bardiche and heighten psychic power. He managed to overpower the Riders, taking out Agito. But once Shoichi awaken with his memories restored, he battles the El in Burning Form after G3-X was injured. The El was wounded by Exceed Gills's Exceed Heel Claw and Another Agito's Assault Kick and then finished off with Agito's Shining Rider Kick. The El of Water was unable to return to the Overlord's body in time and was reduced to a puddle of water to his creator's shock.
EPISODES 33-35, 41-43
A hawk Lord and the strongest of the air-based Lords. Created by the Overlord to ensure no one intervene while he is channeling his power, the El of the Wind uses a longbow named the Merciful Kamtha to fire arrows at his victims, causing them to disappear with only their clothes remaining. The El of the Wind fought Gills after killing off a witness to the Overlord's trance, overpowering him in even Exceed Form and Agito's Burning Form with little trouble. He later aided the El of Ground in defeating Agito Shining Form but before the two Lords could kill him, G3-X and then Exceed Gills arrived to even the playing field. He fought Exceed Gills and G3-X before being wounded by the GX Launcher and killed by Exceed Gills's Exceed Heel Claw.
A lion Lord and the strongest of the land-based Lords, he was created by the Overlord to continue the Lords' task to slaughter those with the potential to become Agito. He wields a sword named the Piousiful Quanda. He was able to turn people into dust with his sand and borrow underground. This El holds considerable strength as apparent from his first encounter with Gills, who engaged him in battle for the death of Risa. He was even able to outmatch Agito, despite switching into his Ground and Burning Forms. However, he was no match for Shining Form Agito, whom mortally wounded him with his Shining Clash attack. The El was then renergized and strengthened by the Overlord, added by the El Lord of Wind to defeat Agito. However, Gills and G3-X soon arrived to even the odds, taking on the El Lord of Wind. The El Lord of Earth was quickly outmatched by Shining Agito and destroyed by Agito's Shining Rider Kick.
The Jaguar Lords are Unknowns based on big cats of the Panthera genus. They killed their victims with a snap of the neck before leaving the corpse on a tree.
The Tortoise Lords are able to swim through the ground like fish in water, their method of killing is to pull the human in the ground, burrying them alive with no sign of the soil disturbed in the process.
The Snake Lords are able to move as blurring speeds at short distances, wind gusts to the normal eye, their method of killing is teleporting the victim several feet into the air, letting gravity do the work for them. Snake Lords
The Crow Lords are able to move as fast as jetplanes in the air, they use aerial-themed deaths from fatal dive-bomb charges to dragging a human into the air and dropping him.
The Zebra Lords use a form of rapid decay as their killing mechanism, using it on normal humans who interfere.
The Jackal Lords are able to move at fast speeds, they use their talent to kill people by severing an artery at the neck, giving the illusion of a kamaitachi.
The Bee Lords using their method of killing is grabbing a person and use a form of matter transference to bury the victim alive in a honey comb wall.
The Stingray Lords are using their method of killing is having a person fall to his/her death via matter transference.
TheFish Lords are using their method of killing is giving their victim a death that seems to look like Diver's Sickness.
The Ant Lords are exclusive to the movie, their method of death is spraying a suffocation-induced liquid in their victim's face. The AntLords are a rarity, due to being able to override the Lords' taboo and kill even normal humans.