The Dopants are normal humans who use Gaia Memories which have the knowledge of everything on the Earth. The Sonozaki Family uses a strange temple underneath their mansion to access the Gaia Memory. They then sell these to the highest bidder or to common criminals, both types used as guinea pigs to study the Gaia Memories as part of the Gaia Impact project. The name comes from the English words "dopant" and "doping". In order to transform into a Dopant, the Gaia Memory is first inserted into a device called the L.C.O.G (Living Connector Setting Operation Gun), also called a Connect Shooter. It makes a USB port-like tattoo called a Living Connector and when a Gaia Memory is pressed onto the Living Connector, it transforms the user into a Dopant. Using a Gaia Memory without a Living Connector has the fatal side effects and a Memory Break won't occur but the Memory will still be ejected.

Special belts called Memory Drivers were developed for use by high ranking members of the Museum to filter out side effects. This weakens the Dopant visibly; high-ranking Museum members use some of the strongest Gaia Memories to more than compensate for this weakening. In some cases, a Gaia Memory may be compatible with its user which, in that case, direct insertion won't corrupt the user and may even make the Dopant even stronger.

To defeat a Dopant, a Kamen Rider has to use one of his Maximum Drive, a finishing attack to forcefully eject and destroy the Gaia Memory, resulting in a Memory Break. Evolved Gaia Memories require a direct strike on its location within the Dopant's body to execute the Memory Break without the risk of killing the user. In order to defeat a Dopant that uses a Memory Driver, the belt must be broken in order to defeat the Dopant.

Gaia Impact
The Gaia Impact is an event that was planned by Ryubee Sonozaki to enable all humans to be made one with the Earth, the result of his fear for the certainty of humanity's future due to the extensive extinctions that he studied as a paleontologist and archaeologist. This plan began when his son Raito (Philip) died after falling into the source of the true Gaia Memory and became a data entity and conduit for its powers, enabling the production of the artificial Gaia Memories. After Philip was saved by Sokichi Narumi and Shotaro from the requests of Shroud, the Gaia Impact was halted until Philip could be retrieved. The source was then used to monitor the use of Gaia Memories, collecting their data to prepare for the Gaia Impact.

After Kamen Rider Double accesses his Xtreme form, it enables the Museum to produce the Prototype Organic Information Controlling Organ Body Gaia Progressor for Wakana, enabling her to transform into ClayDoll Xtreme and become the new conduit for the true Gaia Memory. After Ryubee convinces Philip to help with the family's plans once more after Philip discovers that he has died, Philip is thrown into the source of the Gaia Memory once more, dissolving in data that Wakana absorbed until Shotaro stops Ryubee.

After Philip is separated from Wakana through the Xtreme Memory and Ryubee dies, Jun Kazu takes Wakana with the intent to convert her into data in order to upload her to one of the Foundation's satellites and have her kill all life on Earth that is incompatible with Gaia Memories. However, he must wait until her power as ClayDoll Xtreme must resurface; after discovering that Philip's emotions are linked with Wakana's power level, he decides that the only course of action is to kill everyone close to Philip in order to set the plans into motion. This fails when Shotaro rescues Wakana and, in the process, destroys the building and equipment necessary to cause the Gaia Impact. Afterwards, Kazu himself falls to Double, putting an end to his plan for the Gaia Impact for good. Foundation X stops funding Gaia Memory Research and pursuing the Gaia Impact.

After Wakana discovers that Philip has given up his life for her, she decides to modify the Gaia Impact to do what she believes is best for humanity; she decides to sacrifice her existence to bring Philip back so he can protect the Earth with Shotaro as Kamen Rider Double.

Yousuke Togawa / Magma Dopant
Yousuke Togawa is a man who was fired from his position at Windscale, acquires the Magma Memory, imbuing him with pyrokinetic abilities as the Magma Dopant. However, while exacting his revenge against Windscale, Yousuke is consumed by the Gaia Memory's power and goes on a rampage. Shotaro finds Yousuke at the fifth Windscale building and defeats him as Kamen Rider Double CycloneJoker, executing the Joker Extreme Maximum Drive to destroy the Magma Memory. Before Yousuke can be handed over to the police, he is abducted and murdered by the T-Rex Dopant.

T-Rex Dopant / Marina Tsumura
Marina Tsumura is Yousuke's girlfriend who was also fired from her position as Windscale's top designer, buys the T-Rex Memory with her boyfriend Yousuke to exact their revenge for both being fired. As the T-Rex Dopant, she can cause massive shockwaves with its roars and can use debris to form a robotic T. rex body called the Big T-Rex to increase its powers. However, when Yousuke goes berserk, Marina hires her childhood friend Shotaro to find Yousuke so she can kill him. Once Double destroys the Magma Memory, Marina uses her Dopant form to abduct and murder Yousuke. After Shotaro learns the truth, Marina tries to kill him as she assumes the T-Rex Dopant form. After a brief fight, T-Rex Dopant then transforms into the Big T-Rex and leads Double on a chase around the city. As Kamen Rider Double, Shotaro destroys the T-Rex Memory with HeatMetal's Metal Branding Maximum Drive and hands Marina over to the authorities.

Taizo Kaga / Money Dopant
Taizo Kaga is a life-long gambler who is able to use others' tells to win. He is also the owner of the secret Million Colosseo casino, using his powers as the Money Dopant to enforce payment of debts. By tricking debtors into having them bet their life force in a game of chance, he uses his powers to seal their life force into pseudo-memories called Life Coins after they lose. As he holds the Life Coins in his Dopant body, his destruction would cause all of the people to die. Shotaro and Philip are able to beat Kaga out of Life Coins in a winner takes all game of old maid. After the Money Dopant is defeated and the Money Memory broken by means of the Metal Branding Maximum Drive, the Life Coins are unsealed and everyone is returned to normal.

Genzo Takamura / Anomalocaris Dopant
The childish Genzo Takamura works as the head of one of the many Gaia Memory manufacturing centers scattered throughout Futo. As the Anomalocaris Dopant, he can travel underwater, fire his fangs as if they are bullets, and transform into the Giant Anomalocaris. Due to the fact that councilwoman Miyabi Kusuhara is continuing her late husband's plans to build the Second Futo Tower and Ryubee Sonozaki sees it as a threat to his enterprise, Takamura is given the order to assassinate her. After giving a proto-model of his Anomalocaris Memory, a production-model, to his friend so he can serve as a decoy (defeated by Kamen Rider Double's Joker Extreme), Genzo later kidnaps the councilwoman's daughter Asuka to lure her mother into a trap. However, the Anomalocaris Dopant is defeated by Kamen Rider Double LunaTrigger and his Trigger Full Burst Maximum Drive. One of the members of EXE transforms into an Anomalocaris Dopant and is defeated by Kamen Rider Joker's Rider Punch Maximum Drive.

Ikari / Cockroach Dopant
Ikari is a sociopathic dojinshi artist who runs the Dark Bug Exterminator website, a blog where people write down the names of those they want dead and he carries out the deed as the Cockroach Dopant, writing about his adventures in his self-published manga as the hero "Gokistar". His Dopant abilities include the ability to climb along walls and to move faster than oncoming attacks, much like a cockroach. Only Kamen Rider Double LunaTrigger's homing attacks are able to hit him, but with his speed he steals the Luna, Trigger, Heat, and Metal Memories from Double. Ikari then decided to take the rest of Double's arsenal to become more powerful. However, after Philip learns the Heaven's Tornado dance and uses it against the Cockroach Dopant, the Gaia Memories are retrieved, allowing for the Cockroach Memory to be destroyed by LunaTrigger's Trigger Full Burst Maximum Drive. One of the members of EXE transforms into a Cockroach Dopant and is defeated by Kamen Rider Joker's Rider Kick Maximum Drive.

Yukiko Sasaki / Sweets Dopant
Yukiko Sasaki is a maid at the Sonozaki estate with a sweet tooth that she cannot satisfy, only able to be a food critic instead of a pâtissière because she could not cook very well. In her Dopant form, she is able to fire a whip cream that hardens like cement to trap her enemies. As the Sweets Dopant, Yukiko kidnaps the top pâtissiers hired by the Sonozaki family by dragging them in her "Sweets Cream" state to a small building on the grounds to make pastries only for her. However, when Akiko attempts to weed out the wrong culprit with her sweets, Yukiko kidnaps her with Mai Asakawa, the daughter of her previous victim. Though intending to kill Akiko for disgracing her love for sweets, the Sweets Dopant is battered by Akiko using a chair before Kamen Rider Double finishes her off with HeatJoker's Joker Grenade Maximum Drive.

Sachi Yamamura / Virus Dopant
The Virus Dopant normally turns its user into the vector of a deadly plague that can wipe out entire cities. However, when Sachi Yamamura uses the Virus Memory to save herself from a hit and run, the transformation into the Virus Dopant is interrupted leaving only her consciousness fully enveloped in the Gaia Memory's corruptive influence. These events weaken the Virus Dopant, but also enables it to infect electronics. This ability leads to the creation of the "Infected Car", a formerly wrecked SUV that infects a human with its deadly virus upon impact. When the car is wrecked by Kamen Rider Double, the Virus Dopant begins using its physical form to exact Sachi's revenge on her ex-fiance who she learned was only a con man. After discovering the Virus Dopant's vulnerability to heat, Double HeatTrigger's Trigger Explosion Maximum Drive destroys the Dopant's physical body, causing the Virus Memory's ejection from Sachi's body and its Memory Break.

Tsuyoshi Ageo / Violence Dopant
Tsuyoshi Ageo is Wakana's manager, a weak willed man who loves her in spite of the abuse. Ageo is used by Wind Wave DJ Motoko Saeki in a scheme to force Wakana off the air, giving him the Violence Memory she buys. Overcome by the Memory's influence, Ageo assumes the alias of "Mister Question", targeting certain places of value to Wakana and portraying himself as a stalker. As the brutish Violence Dopant, his left arm is strong enough to destroy anything in its path, even enough to smash through cars. He can compress his body into a wrecking ball-like form called the Violence Ball to cause more collateral damage. Once discovered, he abducts Wakana and is chased after by Kamen Rider Double. Before being defeated by means of LunaTrigger's Trigger Stag Burst Maximum Drive, he leads Wakana to Motoko.

Kenji Kurata / Arms Dopant
Kenji Kurata, part of the Twin Rose burglar team with partner Fuyumi Aso, is hired by Saeko to lure Philip out of hiding. Given the Arms Memory, it turns Kurata into a uncontrollable sadist as he turns his back on Fuyumi and the morals they followed. The Arms Dopant is able to morph his left forearm into a variety weapons such as a gun and carries around a giant blade-like weapon called the Shield Sword. The Arms Dopant has his own personal Honda Valkyrie motorcycle called the Arms Bike. The Arms Dopant goes on a burglary spree and claims to be a Kamen Rider to force Double into the trap, only able to capture Shotaro and Akiko to use as hostages. However, the unexpected return of Kamen Rider W FangJoker, and eventual control of the form, turns the tables with the Fang Streiser Maximum Drive as the defeated Kurata is left for the police.

Akane Egusa / Bird Dopant
Akane Egusa is a middle school girl selected by Saeko to test the limits of one of the newest Gaia Memories: the Bird Memory. In addition to the fact that no one under the age of 20 is allowed to use a Gaia Memory, the Bird Memory can also be used by those without a Living Connector and it has an addictive side effect. When Akane runs away from home, her friend Touma Fujikawa is the first to test the true powers of the Bird Memory out and decides to use it for fun with friends Yuichi Kanamura and Yayoi Kubota until Touma decides to use it to attack people as the Bird Dopant. They are stopped by Kamen Rider Double, and the two boys are taken into the hospital after suffering from some of the negative side effects of using a Gaia Memory without a Living Connector. Later, Akane is overpowered by withdrawal from the Bird Memory and attacks Philip who gets in her way of obtaining it. Consumed completely by the Gaia Memory, Akane is able to access the Bird Dopant's Strengthened Form, only to be defeated after the Nasca Dopant assists Kamen Rider Double in finding the Bird Dopant's weak spot for a direct strike on the Bird Memory by means of CycloneTrigger's Trigger Bat Shooting Maximum Drive.

Kiyoshi Katahira / IceAge Dopant
Kiyoshi Katahira is the son of flower coordinator Makiko Katahira, who received bad press due to her son's actions. Obtaining the IceAge Memory to become the IceAge Dopant with the ability to make absolute zero ice from attacks to clones. Kiyoshi uses it to attack anyone who makes him mad such as Shotaro when he unintentionally shoved Kiyoshi out of the way while looking for Makiko. After his clone is destroyed by Accel's Accel Glanzer Maximum Drive, believing the Dopant to be the one he is looking for, Kiyoshi runs into his mother as she takes the Gaia Memory from him to take the blame for the attack. However, Shotaro uncovers the truth as IceAge Dopant is defeated by Accel's Dynamic Ace Maximum Drive and Ryu Terui arrests Kiyoshi instead of killing him in revenge, only to learn that Kiyoshi is not his target when he discovers that he possesses the IceAge Memory and not the W Memory. Up until this time, the IceAge Dopant is only referred to as the icy Dopant.

Shinkuro Isaka / Weather Dopant
Shinkuro Isaka is the head physician at the Isaka Medical Clinic. Ten years ago, finding no meaning in his life, he encountered Ryubee Sonozaki attacking a group of people as the Terror Dopant. This made Isaka seek to get the Terror Memory for himself, experimenting on himself with several Gaia Memories with various Living Connectors on his body before Shroud gave him the Weather Memory in the hope that he would be powerful enough to eliminate Ryubee. As the Weather Dopant, he is armed with the whip-like Weather Mine and control over the elements: intense sunlight, heavy rain, lightning, tornadoes, and freezing snow. He originally tested these abilities in a series of murders which include Ryu Terui's family, to whom he is only known as the man with the W Memory. Isaka does not use a Gaia Driver, as he feels it only limits the power of Gaia Memories, and he is unaffected by their corruption as he is already intensely psychotic. The Weather Dopant can also withstand Maximum Drives, as he has augmented the Weather Memory with other Gaia Memories' powers. This skill and his knowledge of Dopant physiology makes him an ally to the Museum. After his identity is discovered during his failed attempt to add the Invisible Memory to his arsenal, Isaka takes refuge in the Sonozaki estate where he convinces Saeko to take out her father so she can control the Museum and he can get the Terror Memory. Though he originally sees Saeko as merely one of his pawns, he admits to having developed feelings for her. During his attempt to absorb the Quetzalcoatlus Memory, the Weather Dopant is finally defeated by Kamen Rider Accel Trial's Machine Gun Spike Maximum Drive, shattering the Weather Memory. Shortly afterwards, Isaka's excessive use of Gaia Memories causes his body to become covered in Living Connectors that dissolve him away into nothingness as he tells the Kamen Riders that Shroud will be their end. Shroud later expressed regret to Ryu for giving Isaka the Weather Memory, having no idea of what a monster he would become in doing so.

Aya Kujo / Triceratops Dopant
Aya Kujo is a former FPD officer who transferred to the LAPD under encouragement from her partner Masaki Mizoguchi, whom she loved. After the scrutiny and disappearance of Mizoguchi, Aya returns to Futo and purchases the Triceratops Memory in order to take revenge against the men responsible for Mizoguchi's disappearance and death: the crooked cops Himuro and Ken Akutsu. As the Triceratops Dopant, she possesses superhuman strength, can generate spheres of plasma, and uses the Dinosaur Club as her weapon. However, after killing off Himuro and Akutsu, Aya's revenge shifts to Futo as the Gaia Memory's corruptive powers begin to take hold. She eventually gains the ability to transform into a giant bipedal Triceratops called the Big Triceratops before Kamen Rider Accel stops her with the AccelGunner and its Gaia Cannon.

Sachio Sawada / Liar Dopant
Sachio Sawada is a street calligrapher and poet who uses the Liar Memory to become the Liar Dopant, referred to in urban legends as the Radio Tower Clown. Armed with the Lie Speaks, a staff with a large speaker in a shape of a giant mouth, the Liar Dopant's signature move is converting any lie he says into his Lie Needles, forcing whoever it hits to fall under the Dopant's deception. Though he is paid by Yukiho to help Jimmy win the Fuuuuuutic Idol competition, he turns on her after she fails to pay him his ideal amount, revealing the ruse in front of Jimmy. Once his cover is blown, and his being a fan of Wakana's radio show used against him, the Liar Dopant is defeated through the combined powers of Kamen Riders Double & Accel, with Double dealing the final blow using CycloneJoker's Joker Extreme.

Keio Horinouchi / Puppeteer Dopant
Keio Horinouchi is a children's author who has gained commercial success for his book The Girl and the Dollhouse which he wrote to reflect his feelings for his daughter Rikako who died several months ago. As the Puppeteer Dopant, he uses special puppet strings to take control of whatever he wishes and carries a flute that produces super-sonic waves. He uses these powers to take revenge against those who give his book harsh criticism by controlling his daughter's doll, Riko, as the instrument of his vengeance. He particularally seeks revenge against those who claim he did not truly love his daughter. After being exposed, getting a new puppet in Wakana by Isaka, Horinouchi turns his attention towards Akiko before being defeated by Kamen Rider Double CycloneMetal's Metal Twister Maximum Drive.

Lily Shirogane / Invisible
Lily Shirogane is a popular magician trying to follow in her grandfather Frank's footsteps. To emulate his most famous trick, the disappearing lady, Lily is given the Invisible Memory by Dr. Isaka, turning her into the Invisible Dopant. However, Isaka has modified the Invisible Memory such that she does not turn into a monstrous Dopant and making it impossible to remove from her body. She initially goes to the Narumi Agency for help in finding the man who gave it to her under the pretense that she wishes to have it removed, but instead she wants to be able to control the invisibility. Isaka agrees, stabilizing the Gaia Memory, only because he knows it will eventually kill her and he will be able to take it from her after she dies, giving him the power of invisibility without the Dopant transformation. However, by killing her and using his Engine Blade as a defibrillator to quickly revive her, Kamen Rider Accel removes the Invisible Memory and crushes it.

Hajime Fukushima / Nightmare Dopant
Hajime Fukushima is a college student at Futo University who fell in love with Himeka Yukimura when she called him her "prince". However, he soon realizes that Himeka tells this to any male who assists her, plaguing him with the thought that she will never love him back and giving him insomnia as a result. He acquires the means to become the Nightmare Dopant in order to inflict this same pain on Himeka, by making sure she does not get a good night's sleep in fear of his attacks. In his Dopant form, Fukushima uses his dream manipulation powers to trap all of his rivals for Himeka's affections in their worst nightmares before using a massive dreamcatcher-like net to place them in a coma. Each victim is branded with a letter H on their foreheads, standing for both "Himeka" and "Hajime". Though he fakes being among the victims to get Shotaro off of his trail, Fukushima is found out and his Nightmare Memory is destroyed by Kamen Rider Double LunaMetal's Metal Illusion Maximum Drive.

Maruo Arima / Beast Dopant
Maruo Arima, also known as "Maru", is a bank robber who a decade ago gained the Beast Memory and became the Beast Dopant with superhuman strength and self-regenerative powers. Attempting an armored car robbery at the Futo Dam with his wife Suzuko, the case was investigated by Sokichi Narumi until the evidence went dry and when Isamu Bito turned himself in for the crime. By the present, now rich, Maruo is still looking for a bear statue that holds the Zone Memory. Once it returns to Suzuko's possession, the two return to the Futo Dam to finish their heist. However, the Beast Dopant is weakened by Kamen Rider Double CycloneJoker Xtreme's Prism Break Maximum Drive before being eventually defeated by the Bicker Charge Break Maximum Drive.

Suzuko Arima / Zone Dopant
Suzuko Arima, also known as "Bell", uses the powers of the Zone Dopant to teleport anything she sees in a similar method in moving the pieces of a shogi board. Ten years ago, Suzuko used these powers to assist her husband in his crime wave before she lost the Zone Memory, later found by Sokichi Narumi who then hid it in a bear statue he kept in a vacation cabin. The Zone Dopant is also the first Dopant to have no humanoid form at all, resembling a floating pyramid with an eye at the top. When Shotaro finds it, he confronts Suzuko about having Isamu Bito take the punishment for her crime before she takes it back, enabling her to help Maruo out once more in his battle against Kamen Rider Accel. She is defeated by Kamen Rider Double CycloneJoker Xtreme's Bicker Finallusion Maximum Drive.

Yukie Sudo / Yesterday Dopant
Yukie Sudo is the younger sister of Kirihiko who comes to Futo to take revenge against Saeko Sonozaki for her brother's death. With the powers of the Yesterday Dopant, she is able to force anyone to repeat their actions from the previous day, before the target becomes comatose. Unlike other Dopants, Yukie is not driven insane by the Gaia Memory's influence, which allows her to choreograph her attacks to suit her needs. After attacking several landsharks attempting to buy the kindergarten she and Kirihiko attended, she approaches the Narumi Detective Agency as Yuko Fuwa (resembling the English phrase "Who are you?") looking for her lost cat Kinou ("Yesterday"). Shotaro takes on the case, allowing Yukie to manipulate his actions as Kamen Rider Double to attack Saeko the following day, but Accel saves her at the last minute. Yukie's identity is revealed, and she states that the attack is actually an audition to join the Museum. When she gets close enough to Saeko to exact her revenge, her powers are turned back to her due to Isaka's modifications of the Taboo Memory for such an attack. She is saved after Double CycloneJoker Xtreme's Prism Break destroys the Yesterday Memory, but its side effects finally manifest in total amnesia.

Nagi Shimamoto / Quetzalcoatlus Dopant
Nagi Shimamoto is a worker at the Futo Bird Sanctuary who becomes the unwilling subject of Isaka's experimentation with the powers of the Quetzalcoatlus Dopant. After he kills her father, she is made to be the Quetzalcoatlus Memory's user and both her compatibility with the Memory and her fear of Isaka makes it stronger for him to use later. Isaka makes a copy of the Quetzalcoatlus Memory and uses it on a Red-and-green Macaw to further frighten Nagi by showing a sample of the Memory's powers as the giant Quetzalcoatlus Dopant, the monster Isaka would have her become. The Dopant drags Nagi off until Kamen Rider Double saves her. The copied Dopant is defeated by CycloneJoker Xtreme's Bicker Charge Break. Kamen Rider Accel Trial later destroys the Quetzalcoatlus Memory before it can be used on Nagi to make it more powerful for Isaka's use.

Mysterious Grasshopper Woman / Hopper Dopant
The mysterious "Grasshopper Woman" is a hitwoman who works for the Museum as one of its top two eliminators along with the Smilodon Dopant, originally a normal girl until her mind was rewritten by neuroscientist Satoshi Yamashiro who was kidnapped to serve as a Museum researcher. She has purple hair, is dressed in Gothic Lolita attire, and carries a heart-shaped box full of boiled grasshoppers that she eats and offers to others, often before attacking with her electroshock boots if they turn her down. As the Hopper Dopant, she is able to jump and kick with great intensity. She is called upon by Ryubee to murder Yamashiro when he escapes from the Museum. After mortally wounding Yamashiro, the Hopper Memory is destroyed through Kamen Rider Accel Trial's Machine Gun Spike Maximum Drive. Before Ryu can arrest her, the girl attempts to escape when the Smilodon Dopant kills her so she can not reveal any sensitive information concerning the Museum.

Toru Kawai / Gene Dopant
Toru Kawai is an extremely shy independent film director who becomes the Gene Dopant, able to use the DNA Mixer on his right arm to alter the genetic makeup of anything he touches. Using his power, he made his magnum opus on his own and then tricked theater goers into an empty room to sit through the 7-hour uncompleted film. After being easily defeated, Akiko decides to rehabilitate him by taking control of the movie's production, while trying to hook him up with its star Ai Nijimura who he impersonated beforehand, but this only upsets Toru due to Ai's character being rewritten from the dark figure as originally intended. However, after being used by Wakana to fuse the Gaia Progressor into her body and Akiko beating sense into him, Toru finally speaks his mind. Soon after, Toru gives up the Gene Memory, which is crushed to bits by Kamen Rider Double CycloneJoker Xtreme, and begins working on the movie in his own way with Ai.

Makoto Uesugi / Jewel Dopant
Makoto Uesugi is a popular male model who had a perversed sense of love. When his high school friend Rui Jojima falls in love with their friend Satoru, Uesugi obtains the means to become the Jewel Dopant. Other than his ability to manipulate light and being impervious to most Maximum Drives, Uesugi uses his ability to turn Satoru into a diamond that he wears on his ring. He also forces Rui as his unwilling accomplice, making her seem to be the villain behind his crimes while appearing innocent as he turns many women into diamonds. However, Rui places a monkey wrench in the scheme by framing Detective Jinno and thus start a chain of events that exposes Uesugi and thwarts his plan to kill Rui off and leave town. By then, Philip manages to pinpoint the Dopant's one weakness and defeat him through the Bicker Charge Break Maximum Drive at the jewel's eye crack in his belt. With the Jewel Memory destroyed, Satoru and Uesegi's other victims are restored to normal.

Takashi Soma / Old Dopant
Takashi Soma is a palm reader in Futo who Shroud gave the Old Memory to in a calculated plan to get rid of Shotaro. As the Old Dopant, Soma took on the name of the Ager, offering to age any person his customer hates for the right price, taking delight in his work. In his Dopant form, the Ager uses Old Creak, an ooze similar to the Terror Dopant's Terror Field, to age his target. By turning around, the Old Dopant can switch from the rust-colored form he uses the Old Creak in to a patina-colored faster form that is geared towards combat. Although Shroud states that only the power of Kamen Rider W CycloneAccel Xtreme can defeat the Old Dopant, Accel holds the Dopant for Double CycloneJoker Xtreme to make a direct hit while in his aging state. When the Old Dopant assumes his fighting mode, Accel uses the Machine Gun Slasher to defeat the Old Dopant.
Masquerade Dopants
Masquerade Dopants are Dopants used by the Sonozaki family as guards and other forms of agents. Mass produced Masquerade Memories are distributed to their Gaia Memory salesmen for the purpose of producing more thugs to do their dirty work. The Masquerade Dopants differ from other Dopants as they retain human form, wearing suits with masks that have a spine and rib cage design, resembling the bony design of the Dopant Gaia Memories. Masquerade Dopants are also weaker than other Dopants, and are completely destroyed when defeated, and without the need for a Maximum Drive.

T2 Dopants
In the movie Kamen Rider W Forever: A to Z/The Gaia Memories of Fate, the Dopants use T2 Gaia Memories, 26 special Gaia Memories developed by Foundation X based on Fumine Sonozaki's findings. Though originally in the possession of Jun Kazu before giving it to another member of the Foundation to take to their headquarters, the six of the T2 Gaia Memories end up in the possession of mysterious terrorist group NEVER while the rest are scattered across Futo. Unlike the original Gaia Memories, these memories appear to have some sentience, injecting themselves into people who are compatible with them (Watcherman and Santa-chan becoming the T2 Violence and IceAge Dopants) or causing a Living Connector to appear on someone's skin (Queen). There are also T2 Gene, Nasca, and Weather Dopants. They are all individually flight-capable, and can be summoned to and from one location with the T2 Zone Memory's Maximum Drive. Further, the T2 Memories are extremely resistant to destruction, as a normal Memory Break does nothing to impede their functionality. All 26 T2 Memories are destroyed at the climax of the film by Kamen Rider Double CycloneJokerGoldXtreme.
Hyper Battle DVD Dopants

Izo Aida / Oyakodon Dopant
In the Hyper Battle DVD, Izo Aida, the master of the OmuriFu omelette rice shop owned by his daughter Eriko, transforms into the Oyakodon Dopant; his Gaia Memory possessing the combined powers of both the Egg Memory and the Chicken Memory. Initially known as the "Donburi Dopant", Izo attacks the Fuumen stand so that Omuri Fu becomes Futo's number one eating establishment and over powers Double and Accel when they meddle. But once Philip discovers the Dopant's true nature, Double CycloneJoker Xtreme defeats the Dopant with the Bicker Charge Break Maximum Drive. Luckily, the master of Fuumen decides not to press charges against Izo, having him work at his stand to pay back for the damages and help him start anew. Aida's transformation into the Oyakodon Dopant reflects Double's transformation sequence with the words "Fuwafuwa" and "Juicy" appearing. The design of the Oyakodon Dopant is based on the winning entry of a Dopant drawing contest for Televi-Kun magazine and the Oyakodon Memory is based on the CycloneJoker Memory that came with the July issue of Televi-kun.
Series:  Kamen Rider W