Swartz

"I care not about your opinion."

- Swartz when asserting his dominance

Swartz (スウォルツ), alternatively spelled Suworutsu or Schwartz is the main antagonist of Kamen Rider Zi-O. He was the leader of the Time Jackers and the older brother to Tsukuyomi. After being rejected of being chosen as the next heir to a royal family in favor for his sister, he erased her memories and took her and himself in a different timeline. From then on, Swartz has been instigating a series of events in order to fulfill his own agenda as King and is responsible for the rise of Oma Zi-O.

After absorbing Tsukasa Kadoya's powers, he becomes Another Decade (アナザーディケイド), an Another Rider derived from Kamen Rider Decade.

History
In a different timeline, Swartz is the oldest child of a royal family, with Alpina being his younger sister. However due to unknown circumstances, Alpina is chosen to be the successor to the throne, even when Swartz's power is greater. This caused Swartz to become jealous and erase his sister's memories before dumping her into Oma Zi-O's timeline on 2068. The resistance finds her and named her "Tsukuyomi".

On April 24, 2009, he appears in front of a tour bus full of children born in the year 2000, which is driven by Tsukasa Kadoya. On the bus, elementary school age Sougo Tokiwa and Hiryu Kakogawa are also present, apparently going on a school trip. Swartz stops time and gets on the bus, causing Tsukasa to lose control. Swartz then states that the event is a trial for the children inside, whom he deems eligible to become future kings. Sougo's father, along with Hiryu's father, stands up to Swartz, but they are swiftly pushed aside by his power. A young Sougo also summons the courage to fight against the Time Jacker, but to no avail. Swartz lifts the boy up and threatens him. At the same time, a time-travelling Tsukuyomi makes her presence known to Swartz as she shoots her Faizphone X gun at him in order to protect the young boy. Swartz uses his hat to block the shot, and then pushes Tsukuyomi away, saying that she was an "uninvited passenger". Swartz later teleports the children to a time/place where the world is being destroyed by Dai Mazines, leaving the adults to die as the bus crashes.

As the Dai Mazines are destroying the children's surroundings, Swartz tells the children that only the future king can survive the event. Rubble is about to hit Hiryu, but Sougo, not wanting him to get hurt, awakens his powers, stops time and saves him from the falling rubble. Right after that, Sougo uses his sheer will to make a Dai Mazine turn to dust. Witnessing Sougo's potential, Swartz appears next to Sougo and says to him that it was his destiny from birth to become a king and save the world. He then alters Sougo's mind, making him think that the entire ordeal is just a dream. This explains Sougo's "childhood dream" of a man in black, saying he would definitely become a king in the future. Swartz then transports all the children back to the scene of the bus crash, apparently making it look like a normal traffic accident.

In the present, Swartz first appears during the case of Ryusei High School. He talks to his subordinates for a short moment, offering some chocolate to Heure (in a condescending manner) before leaving. He is responsible for making Ryuichi Sakuma (who, at that point, has already had the power of Another Faiz thanks to Ora earlier) become Another Fourze. As Ryuichi's Another Faiz powers start to fade away gradually, Swartz offers him the chance to become Another Fourze, so that he may still be able to save his girlfriend. Ryuichi is perfectly willing to accept the deal.

During the Another Wizard incident, Geiz Myokoin, on the way to deal with the threat, unexpectedly encounter the Time Jacker on the top of a building. Swartz attempts to take Geiz out by pushing him out of the rooftop and letting him fall to the ground. Luckily for Geiz, Woz arrives just in time and saves him from Swartz. The Time Jacker asks when has the two become allies, then remarks that the arrival of Woz is not within calculation. He promptly takes his leave without causing further trouble.

Later, Swartz has a brief talk with Heure and Ora, after the fall of Another Wizard. He says that Zi-O can become the King because he believes in his ambition, and never once doubts his ambition. This prompts Heure to search for the ideal candidate for Another OOO, a man who also never once doubts his ambition: Kuroto Dan, who is originally Kamen Rider Gemn.

As Geiz decides to detach from Sougo and kill him for the sake of the future, after witnessing his actions in the OOO tribute arc, Swartz invites the Kamen Rider to join the Time Jackers in overthrowing Zi-O. Geiz states that he just wants to save the future from the tyranny of Oma Zi-O, but Swartz reminds him of his defeat at the hands of Sougo earlier, and suggests that Geiz should accept their invitation. Swartz takes Geiz's silence as a "yes". Swartz takes Geiz to see his newest creation: Another Gaim. He thinks that with the power of Kamen Rider and Another Rider combined, Zi-O will definitely be defeated. However, as Another Gaim starts attacking bystanders, Geiz jumps out and saves them from it, realizing that he can never join the Time Jackers due to their disregard for human life. Swartz leaves the scene, disappointed, as he previously thinks Geiz was "more intelligent" than this.

Meanwhile, Woz, seeing that his master has messed up the timeline quite a bit by time travelling, decides to side himself with Swartz in order to get him back on to the path of becoming Oma Zi-O. He provides the Time Jacker with the information on Sougo's plan to acquire the Gaim Ridewatch. When Sougo is about to use it, Swartz appears right behind him. Sougo shoots him, but he stops the bullets midair and bounces them back at Zi-O. Swartz then takes the Ridewatch and throws it into Helheim forest.

After the fall of Another Gaim, Woz comes to find Swartz and the gang again at a coffee restaurant, offering his assistance so that he may lead Sougo back on the path of becoming Oma Zi-O. He provides them with information on the Destroyer of Worlds, who can be a threat to his King: Tsukasa Kadoya.

After the defeat of Another Ghost, Swartz notes that Oma's Day is coming even earlier than in his own original timeline. He wonders whether Zi-O is aware of their interference.

When Sougo has finally met his future self, he becomes terrified of what he might become, so he destroys his Ziku-Driver. Due to this act, the Time Jackers are free to do as they want. However, Swartz wants to remove everything that still has the potential to cause them harm, so he reactivates and brainwashes Oma Zi-O's then-inactive servant, Kasshin, to kill Sougo for good. Fortunately, Geiz and Tsukuyomi arrive in time to save Sougo and convince him to take up arms once again. Sougo agrees, but his actions cause the existence of a new timeline where Zi-O is defeated by Geiz.

At the start of the new year, 2019, Swartz is seen with his subordinates, who ask him what to do from then on. Swartz is aware of the changes in the original timeline caused by Sougo's earlier actions, saying that the changes might be beneficial to them. He then hands Heure the Another Shinobi Ridewatch as a "New Year's gift". Heure would later use it on Rentaro Kagura.

Due to the aforementioned changes in the timeline, another Woz, dressed in white, arrives from the future where Oma Zi-O does not exist. He swears loyalty to Geiz, saying that Geiz is the one who will defeat Zi-O and bring about his future instead of the original future where Oma Zi-O is supposed to rule with an iron fist. He transforms into Kamen Rider Woz and defeats Another Shinobi. Swartz seems to have expected this Woz's arrival, and reactivates the Another Shinobi Ridewatch.

Later that night, Swartz meets a distraught Rentaro, telling him not to worry, as the Riders have no way to obtain the corresponding Ridewatch to defeat him, as Kamen Rider Shinobi was technically not even born yet. However, Rentaro asks Swartz whether he can really use this power to protect the weak or not. Swartz's only response is that Rentaro, at the time, is basically invincible.

The next day, as Another Shinobi wreaks havoc, White Woz comes and sees Swartz. Swartz notes that it is impossible for the former to acquire Shinobi's powers because of the reasons mentioned above. White Woz does not waver, and he suggests asking Oma Zi-O. Zi-O faces and defeats Another Shinobi once again that day, but Swartz states that his effort is useles as he reactivates the Watch again. However, after the third defeat, Rentaro begins to resist Swartz's attempt at transforming him, thanks to Zi-O's encouragement. Swartz still forces the watch on him anyway. Nevertheless, White Woz has managed to create the Shinobi Miridewatch, much to Swartz's surprise. Another Shinobi is finally defeated for good by Kamen Rider Woz.

As Another Quiz is defeated at the hands of the Riders, Swartz tells Heure that White Woz's appearance has caused them a lot of trouble lately, while Heure keeps throwing a rock at a mirror again and again using his time-stopping and reversal powers. Swartz gets agitated, then asks what the young Time Jacker is doing. He says that he is trying to unlock the Mirror World from the information that Tsukasa has given him earlier. Heure meets Dark Shinji inside the Mirror World, and offers him the Another Ryuga Ridewatch.

When Another Kikai appears in the city, the Time Jackers do not know where or when it comes from. Swartz intends to harvest its powers, by turning it into an Anotherwatch. As Zi-O destroys Another Kikai for the second time, Swartz catches the "bug", which is the catalyst for its power, and forces it onto Heure, so that he may be able to gain an Anotherwatch later. He even challenges the Riders to create the Kikai Miridewatch before he does. The Riders eventually harvest the Kikai Miridewatch successfully, and manage to destroy Another Kikai once and for all.

With the three Miridewatches at hand, White Woz has finally been able to create the Geiz Revive Ridewacth for his savior. Swartz notes to Heure and Ora that Regulus will be at its brightest at the end of April, and that Oma's Day is coming closer and closer. Swartz decides to create Another Zi-O by using the Zi-O Anotherwatch on Hiryu Kakogawa, the child from the bus accident back in 2000. Apparently, Hiryu does not know the truth behind the accident, and he assumes that Sougo is the reason why his parents are dead. This action makes Heure extremely concerned, and starts to think that Swartz may have a hidden agenda.

Swartz later meets White Woz, who has lost his powers to Black Woz, stating that the Oma's Day that he wants to bring about will not be likely to occur. White Woz compliments Swartz on his "craftiness" in the matter, and everything will eventually be in Swartz's favor in the long run. White Woz also notes that he needs to follow the Time Jacker's actions closely from that time on. Swartz only replies that he does not ask for White Woz's opinion.

On another morning, Swartz allows White Woz, now an ally, to use the Another Blade Ridewatch freely. However, he also notes to Woz that, to a human, there are ones who use it and ones who are used by it. The former group will think about righteous purposes, and the latter group will fail to understand their own purposes in life. Swartz wonders which group White Woz belongs to. After the defeat of Another Blade, Swartz and his two subordinates are seen in a coffee shop, with Heure wondering what Swartz has been up to all this time. Swartz takes no notice of his opinion, only remarking that it is inevitable to collect more Ridewatches, as Sougo Tokiwa has already experienced Oma's Day and is still on his way to become a King. Ora responds that Swartz's words do not sound pleasant at all, but Swartz assures that a plan is in motion at the time.

As Another Agitos are assauting the G3 team, Swartz stands on the sideline, and watches the whole event happen. When Tsukuyomi is about to be hit by one of the Another Agitos, she manages to inexplicably freeze time to stop the monster in the air, much to Swartz's surprise and bewilderment. Swartz then decides to "test" Tsukuyomi once again.

Swartz approaches Tsukuyomi as the latter is sitting on a bench. He asks whether the young girl is feeling anxious because of her power. Tsukuyomi says it is none of the Time Jacker's concern. However, Swartz reaffirms that it is indeed his concern, because he has taken his time to come and test her. Just as he finishes, an Another Agito appears and forces Tsukuyomi to run. Swartz wants the girl to show him her power again. He asks for her real name, as "Tsukuyomi" is just an alias, but she has no clue because she has lost her memory. Swartz remarks it would be better if she does not remember her past, as she would be happier that way.

When Shouichi Tsugami comes to save a cornered Tsukuyomi, Swartz compliments him on his performance as Kamen Rider Agito, but he also reveals that he has created the Another Agitos in order to be able to harvest the power of the original Agito by force. He then orders the Another Agitos to attack Shouichi. Shouichi transforms into Agito Storm and Flame Form and manages to gain the upper hand. However, Ora and Heure interrupt and hold Tsukuyomi hostage. Agito is then distracted, and knocked down by an Another Agito. Swartz says he did not ask for his subordinates' support, only for them to reply that Swartz's plan is not very effective in the first place. After Heure steals the power of Agito and creates an Agito Ridewatch, Tsukuyomi accidentally stops time once again, freezing everyone, including Swartz, much to the villain's bewilderment. Heure still manages to take the power of Agito and leaves with it. Tsukuyomi wants to know whether Swartz is aware of her past or not. Swartz does not respond and silently exits the scene with Ora.

Later, as hordes and hordes of Another Agitos are terrorizing the city, Woz comes and talks to Swartz about Tsukuyomi's time powers. He asks whether the Time Jacker wants to turn the young girl into one of them, to which Swartz replies that he has nothing to do with the matter. Woz knows that the time manipulation ability originally, and exclusively, belongs to Swartz, and only he can bestow such a power on someone else. Swartz affirms this, hinting that Tsukuyomi and him may be from "the same group".

After the birth of Another Kiva, who starts to disobey Ora, Swartz is seen eating ice cream with Heure, commenting on Yuko's ferocity with amusement. This does not last long, however, when he is alarmed of the advent of a new and formidable foe from space: Kamen Rider Ginga. When Zi-O Trinity is utterly defeated by the space Rider's overwhelming power, Swartz suggests that the protagonists team up with him, because Ginga's presence is a huge hindrance to both sides. However, he secretly plans to take Ginga's powers for himself. The group then goes to Yuko for extra assistance. Swartz compliments Yuko on her looks, and even politely addresses her with honourifics. Yuko agrees to help defeat Ginga on one condition: Everyone must kneel before her. Swartz complies, and even forces Ora to kneel with him and Heure. Nevertheless, Yuko decides not to help anyway and leaves. Swartz angrily asks whether she knows how severe the situation is, only for Yuko to say that she does not care for his opinion, much to the Time Jacker's shock. Heure is amused at how his senior's words are thrown right back at him.

During the battle with Ginga, the Time Jackers offer support by providing cover fire. Swartz and Woz manage to land two hits on Ginga, just as dark cloud start to emerge. Ginga, being powered by the sun, is turned into stone and immobilized. As the clouds clear, Ginga returns to action, overpowering Swartz, Woz, Geiz Revive and Zi-O II simultaneously. Yuko finally decides to step in and help at this point, but she is also no match for Ginga's might. However, she is able to distract him long enough to create an opening for a triple Rider Kick. Ginga flees into space, and some of the Rider's essence manifests itself in the form of a Miridewatch, which lands on Swartz’s hand. Woz, having anticipated this all along, swiftly takes the Ginga Watch and escapes to fight Another Kiva, leaving Swartz agitated.

As the Worms are beginning to terrorize the city, Tsukuyomi uses her time powers to save a mother and her child from some falling rubble. Swartz stands on top of a building and observes, noting that her power is becoming more powerful, and that her "awakening" is just a matter of time. Tsukasa Kadoya suddenly makes his presence known to Swartz, asking what the Time Jacker really means by "awakening". Swartz even dares Tsukasa to "keep playing detective", to which the Rider responds that he certainly will find out the relationship between Swartz and Tsukuyomi.

Swartz appears before the duo when they are in the year 2058 searching for the truth, and knocks out an untransformed Tsukasa, while giving back Tsukuyomi the Fourze and Ginga Ridewatches (both of which have previously been stolen with the help of Another Kabuto). He tells Tsukuyomi to come back to the current timeline to help Sougo and Woz destroy the gigantic meteorite which is about to crash into Earth, as the Time Jackers do not wish for the Earth to be destroyed. He notes when the King of Time's power and her power unite, a brand new era is able to begin. As he returns to the current timeline, he sees that the meteorite is just another test for Tsukuyomi to awaken her true power.

After Zi-O successfully obtains the power of all the previous main Heisei Kamen Riders, Swartz chooses not to play around anymore and starts to heavily tamper with the timeline, resulting in a new one where everybody (but Woz, the Time Jackers, Hiryu Kakogawa, Daiki Kaito and Tsukasa Kadoya) has lost their memories about Sougo. This timeline is ruled with an iron fist by none other than Hiryu Kakogawa himself, complete with a new and improved power set in the form of the Another Zi-O II Watch. He entrusts Ora with the duty of standing by the new King.

Daiki Kaito sees the new and chaotic timeline as an opportunity for him to steal more treasures, so he breaks into Hiryu's castle and steals the Another Zi-O II watch from him. Just as he is about to escape, Swartz stops time then returns the Watch to Hiryu. He ensures Hiryu that he can be counted on to deal with matters other than destroying Zi-O. After Hiryu and Ora leave, Swartz brainwashes Daiki and gives him time powers, telling the intruder that he has an even better treasure for him to steal. This later proves to be true, as Daiki is able to easily steal the GrandZi-O Ridewatch with his new time powers bestowed upon by Swartz.

"Don't be afraid. I just want to ask you a few things... My dear little sister."

- Swartz reveals his relationship to Tsukuyomi in person

As Zi-O II, without access to his final form, Sougo fights a hopeless battle against Another Zi-O II, Geiz deciding to step in and save Zi-O, taking him away from the battle. Swartz mockingly asks Hiryu whether he has lost to Zi-O. Hiryu justifies by pointing out that Sougo decided to run away, rather than continue the fight. Swartz pushes him further with his sarcastic questions, then he turns his eyes on Tsukuyomi, apparently having some plans to use her to his advantage. The girl realizes this and runs. Ultimately, Heure is able to catch Tsukuyomi and bring her back to Swartz. At the castle, Swartz reveals the fact that he and Tsukuyomi are siblings, much to both Heure and the girl's surprise and bewilderment.

Swartz soon exposes to her that they are both members of a royal family in an alternate timeline, that the time manipulation powers are a gift bestowed upon this royal family's bloodline, and that the "King"'s title will eventually belong upon him. Heure is shocked by this statement, because Time Jackers are supposed to dethrone Oma Zi-O rather than making someone among themselves the ruler. Swartz only smiles in response as he knocks Heure down. Just then, Ora also enters the room, asking why Daiki Kaito can use time powers. As she demands answers, the Time Jacker superior proceeds to take away her own powers, much to Heure's shock. Swartz discloses that he is the one who gives Heure and Ora powers in the first place, so naturally he is able to take it back as well. Heure, still appalled, grabs the Faizphone X and shoots Swartz, and manages to escape. Swartz tells Daiki to dispose of them, which he agrees to do.

Now that Swartz and Tsukuyomi are the only ones left, he continues to tell her about her past. He states that although his time power is the strongest in the family, Tsukuyomi is chosen to become the ruler instead of him, so he wipes his sister's memory and sends her to Oma Zi-O's timeline, hoping for her to get herself killed. In fact, he is surprised that his sister actually manages to survive until this day. Swartz attempts to take away Tsukuyomi's time power for himself, but Woz arrives in time to disrupt the process. However, Swartz knows from the start that Woz only follows Hiryu to spy on him, and subsequently knocks Woz crashing into a wall. Eventually, Swartz is able to absorb all of Tsukuyomi's powers into himself, becoming drastically more powerful as a result.

He is later seen observing Decade and Diend's battle. Just as Decade is about to finish Diend off, the latter stops time, freezing the former in place. Swartz pulls out a blank Anotherwatch and successfully takes away the power of Kamen Rider Decade.

After Sougo defeats Another Zi-O II and resets the timeline, Swartz allows Daiki to take the Another Zi-O II Watch as his treasure. He tells Hiryu that he has never had the qualities of a King to begin with. He also assures Tsukuyomi they will meet again and that he has taken Tsukasa's powers. With the Another Decade Watch in his possession, Swartz proclaims that his reign will finally begin.

Swartz makes his next move as he creates Another Drive and has it terrorize around the city. It is, however, defeated by Zi-O and Geiz, revealing Ora as the Another Rider's host. Heure expresses his confusion, as both him and her have agreed to conspire against their former leader earlier. Just then, Swartz appears and transforms into Another Decade. He uses a Dimensional Wall to transport Zi-O and Geiz to another world, where he summons Kamen Riders Rey, G4, Fuma and Dark Ghost to fight the duo. Swartz then proceeds to overpower them with his newfound power.

Personality
Of all the Time Jackers, Swartz is extremely cold and calculating, always having tricks up his sleeve. He is also very arrogant and does not leave room for anyone "lower than him" to express their opinion. This is due to him wanting to become regardless of what Ora or Heure thinks of their or his actions. He is solely motivated on creating the new King replacing Oma Zi-O in the future and he creates Another Riders by force. Any Another Rider hosts are nothing but mere guinea pigs to him, and even Heure is no exception. This is later affirmed by White Woz, who shortly before his disappearance had warned Sougo's team that Swartz is up to something dark. Eventually, it is revealed that Swartz wants to set himself up to be the new King.

Swartz is a no-nonsense, serious and ruthless man who is more than willing to go through extreme lengths to achieve his goals, even if it means hurting his allies, his own blood, and innocent children. This is shown through his actions in 2009 where he sabotaged the bus just to "test" the children and indoctrinate Sougo into becoming a king. He is cruel, heartless, and treacherous enough to betray and steal the powers of Heure and Ora, making the Another Riders go after them to kill them. This is further extended to the point where he shows no remorse or guilt in hurting his own sister to get what he wants, and simply laughs in joy after he steals her powers and she falls unconscious. In fact, he is even slightly surprised when his sister does not get herself killed in Oma Zi-O's timeline.

On a couple of side notes, he becomes flabbergasted if someone with higher authority than him appears, and he does not mind allowing that person to voice out their opinion, much to Heure's amusement. Swartz is not without showing any sign of fear and/or dread, evident when he sensed the presence of Kamen Rider Ginga's arrival on Earth.

Powers and Abilities

 * Time Travel: He can freely travel back and forward in time. He can even travel to points in alternative timelines, which not even a Time Mazine could go to. Apparently, he does not seem to need a Time Mazine to do this, as shown when he teleports the children on the bus to another space/time.
 * Temporal Awareness: He is the only one who somehow knows about White Woz's timeline and other ones.
 * Time Manipulation: Being a member of the royal family, he possesses the innate power to stop the movements of everything around him. When this ability is on, he can, completely or partially, spare people of his choosing from its effect. He states that his time manipulation power is the strongest in his royal family.
 * Power Bestowal: Swartz can bestow time manipulation powers to others through a painful method, albeit a weaker version of himself's. He can also take these powers away if he so wishes. He can also remove the powers of other royal family members, and will become exponentially stronger if he does so.
 * Memory Alteration: Swartz also has the ability to alter and or erase memories. He altered Sougo's memories in 2009 so that he'd only recall such event as a dream. He also erased Tsukuyomi's memories before dumping her into a different timeline.
 * AI Reactivating: Swartz demonstrates the ability to revive and put Kasshin under his control with a touch in the head in order to kill Sougo Tokiwa.
 * Telekinesis: Swartz is also able to use telekinetic powers as means of offensive ability.
 * Keen Manipulator: Over the course of the series, Swartz has proven himself to be more than capable as a schemer. In fact, a majority of the events that has happened in the series is the result of Swartz's manipulation so that he is able to crown himself as the new king.

Weaknesses

 * Tsukuyomi: Tsukuyomi is also a member of the royal family, her time manipulation ability can also stop Swartz in his tracks, something that Heure and Ora cannot do as they are not royalty since he has bestowed them these powers to begin with. Tsukuyomi also can steal time manipulation abilities from others as well, and can very well do it to Swartz.
 * Tsukasa Kadoya: Because Swartz has the ability as Another Decade to open Dimensional Walls, those walls can be used against him as Tsukasa is able to freely manipulate Dimensional Walls even without his Rider powers.

Forms
Another Decade

"Decade!"

- Transformation announcement


 * Rider Height: 192 cm
 * Rider Weight: 83 kg
 * Creator: Himself
 * Year of Origin: 2019
 * Position of year: Right Pectoral (Underneath Name)
 * Name and position: "DECADE"; Right Pectoral (Above Year).


 * Powers and Abilities


 * World Creation: Another Decade's existence brings forth the materialization of the World of Lost Possibilities known as Another World, a world under Another Decade's control with an army of Dark Riders that follow his will.
 * Dark Rider Summoning: Another Decade can summon Dark Riders from his Another World. They're copies of their counterparts from the main universe, but loyal to him.
 * Dimensional Teleportation: Another Decade can teleport themself and their opponent to a random location of their choosing using Dimensional Walls.

Appearances: Zi-O Episodes 41-43 (statue), 44-45

Equipment

 * Anotherwatch - Transformation trinket

Time Jackers:

 * Heure: Swartz sees Heure as nothing but a mere child. He also does not mind using Heure to be the host of Another Kikai. After Swartz reveals his true intentions and takes Ora's powers, Heure begins to see Swartz as an enemy, vowing to get even with him for his manipulation.
 * Ora: Ora sees Swartz as her superior, and shows some dislike towards him. On the other hand, Swartz allows Ora to do as she pleases, even going as far as to reuse Heure as Another Kikai's host. However, Ora is not beyond being spared by Swartz, as after he takes away her powers, he sent Another Riders and Diend to kill her and Heure. Ora comes to resent Swartz because of this, even returning the GrandZi-O Watch to Sougo to thwart Swartz's plan.

Enemies:

 * Sougo Tokiwa/Kamen Rider Zi-O: Perhaps the biggest obstacle to him, he works to dethrone him. Despite this, it is revealed that Swartz is the one responsible for putting Sougo on the path to become a king. His reason of doing this is currently unknown.
 * Geiz Myokoin: Briefly these two have the same goal and Swartz, along with Ora even invites Geiz to join Time Jackers. Thankfully, Geiz wises up and views the man as his enemy.
 * Tsukuyomi: Tsukuyomi is Swartz's younger sister. Not much is known about their relationship in the past, though it is implied that they used to have a good relationship until some point. When Tsukuyomi is chosen to be the new ruler of their bloodline, Swartz's jealousy gets the better of him, and he erases Tsukuyomi's memories and sends her into a dystopian timeline, hoping that she will kill herself there. However years later, Swartz is not aware that she has managed to survive until her powers reawakens. With Tsukuyomi unprepared to face the fact of their relationship, Swartz takes advantage of this and stripped her of her powers. Tsukuyomi genuinely desires to put a stop to her brother's evil schemes.
 * (Black) Woz: Seeing the man as nothing more than a nuisance, Swartz does not care much about Woz, yet when he offers to help, if their goals are lined up similarly, he will work with the record keeper until their objectives are met. Woz is also seemingly the only one wise enough to be aware of Swartz's tricks up his sleeve, as shown when he steals the Ginga Watch from Swartz.

Others:

 * Hiryu Kakogawa: Using him to try and destroy Sougo, Swartz creates Another Zi-O using a child from the bus incident that he himself caused, using his own hate and rage to control him. Hiryu is unaware of the fact that Swartz was the one who caused the accident that cost him his parents. In fact, Swartz only sees Hiryu as nothing but another means to an end. When he has outlived his usefulness, Swartz discards him at once, even allowing Diend to take away his Another Zi-O II Watch and mocking him for his failure, saying that he has never had any qualities of a King to begin with.
 * (White) Woz: Swartz and White Woz joined forces in discreet after the latter loses his power as Kamen Rider Woz to his counterpart. Both are now hellbent to create a future they desire. However, after several repeated failures, Swartz gives White Woz one last chance and exclaim that whether he was using Swartz or being used by Swartz is up to him. Upon Zi-O acquiring the Zi-O Trinity Ridewatch from White Woz and he himself was about to be erased, he warns his counterpart about Swartz’s plan and to be cautious to him, effectively betraying Swartz.

Portrayal
Swartz is portrayed by Kentaro Kanesaki (兼崎 健太郎).

Etymology

 * Swartz is a portmanteau of Swatch, a brand of Swiss watches, and quartz, the mineral used to regulate the electronic oscillator installed in clocks and watches.