History Characters / KamenRiderZiOSougoTokiwa

* ProtagonistCenteredMorality: Sougo swore to avoid ever becoming Oma Zi-O by declaring he would instead become the greatest and most beloved overlord in history. Oma Zi-O swore the same thing, and honestly believes he ''succeeded''.

* AuthorityEqualsAsskicking: [[BadassBoast As noted by the man himself]], he has power worthy of having the title "Demon King". Each and every appearance of his displays overwhelming might on a level no one in the series can even ''dream'' of matching.

* SuperPowerLottery: With the combined powers of every single Heisei Rider and absolute control over time itself, Oma Zi-O is a leading contender for the king of this trope.

* GutturalGrowler: When Sougo adopts his [[spoiler:Oma Zi-O]] form, his voice comes off as being frighteningly deep and menacing, making him sound like the supposed Demon King of Time he'll become in the future.

* SuperPowerLottery: With the combined powers of every single Heisei Rider and absolute control over time itself, Oma Zi-O is a leading contender for the [[JustForPun king]] of this trope.

* TenMinuteRetirement: After meeting his future self, Sougo decides to destroy his Driver in order to prevent himself from becoming Oma Zi-O. Thanks to the Time Jackers, who want him dead, and Woz having a back-up Driver in the event his old one should be destroyed, Sougo's decision to give up being a Rider lasts only for a day. [[NiceJobBreakingItHero Of course, this also means Oma Zi-O is restored to existence]].
* AllLovingHero: {{Zigzagged}} at first, played straight eventually. Sougo hates the idea of anyone getting hurt even willing to take a hit while unpowered to protect a child and he even reveals his dream of being a king is to protect everyone around him. But as the show goes on, Sougo is shown to not be as kind as he appears being an excellent manipulator and having moments of selfishness underneath it all. [[spoiler:His mirror self even lampshades that he's not as nice or optimistic as he appears to be. The last episode however this trope became played straight, as even after becoming Ohma Zi-O and defeated Swartz, he used it's abilities to destroy and recreate time and space, reviving both his comrades and the Time Jackers in the process in the rewritten timeline]].

* AmbiguousInnocence: Sougo's optimistic innocence is sometimes played to a disturbing degree as he waves off the bad stuff going off to concentrate on what he wants, starting out when he claims it's a bummer his future self is evil. Then there are his interactions with [[Series/KamenRiderExAid Kuroto Dan]], whom he takes for a kingly role model. That involves just waltzing over the latter's obvious evil and insanity. It's not as much that Sougo wouldn't notice those things, they just don't bother him because he believes they can't hurt him and it takes time, effort and occasional reminder to get him to think about the other people affected.

** Another Drive learns that the hard way after Sougo finally snaps and lays down a NoHoldsBarredBeatdown for [[spoiler:mocking Heure's death]].

* BreakTheCutie: ''Back to 2068'' has Sougo see just for himself what becomes of the future and realizes that he had been ''grossly underestimating Oma Zi-O's damage to the world''. Adding insult to injury, when he meets his future self in person, Oma Zi-O echoes what Sougo swore he would be, a benevolent and beloved demon king...and he thinks he succeeded. This leads him to throw away his Ziku Driver and quit his dream of becoming a King. Though that lasts about a day as the Time Jackers want him dead anyway, and Geiz promises him to keep him on the right path.
** ''World, Reset'' is even worse because Sougo is erased from history and loses everything he had. No-one recognizes him anymore aside from his status as overlord and Zi-O, so they naturally try to murder him. The world is in ruins, his self proclaimed ArchEnemy rules as the actual king and there doesn't seem to be anything he can do about it. He just lets Geiz maul him so everything would be over.
* BrilliantButLazy: Within the first dozen episodes, it's shown that his grades aren't bad due to a lack of intellect, but rather a lack of direction, and whenever it comes to his goal of kingship, or to protecting people, he can be dangerously cunning, so much so that it's hard to see where [[FutureMeScaresMe Oma Zi-O]] ends and Sougo begins.

* CannotSpitItOut: Somewhat. After Geiz and Tsukuyomi left Kujigojido, Sougo felt particularly lonely, which these feelings have gotten worse as he bumps into the two on multiple occasions, which often result in him being left alone. Despite all this, he merely says he's fine. It isn't until Junichiro builds up the courage to actually scold him for hiding these feelings and insist he simply just say so, and advises that if he cannot admit he is lonely when he is, he will become a king oblivious to the pain of others.

** He is a NightmareFetishist when it comes to weird stuff going on or meeting other Riders in middle of chaos caused their evil copies.

** The previous Kamen Rider, [[Series/KamenRiderBuild Sento Kiryu]], was both an InsufferableGenius and a GeniusBruiser, while Sougo is an OrdinaryHighSchoolStudent who happens to be an EvilOverlord in the future. While Sento designed his team's equipment on his own [[spoiler: based on an alien Driver]], Sougo is provided his own driver by Woz [[spoiler:that happens to be the predecessor of his future self's Driver]].
** Because of their similarities as TheChosenOne, he is this to [[Series/KamenRiderWizard Haruto Soma]]. While Haruto, who is a ExperiencedProtagonist, wants to be a HopeBringer to everyone he knows; Sougo, who only got his powers, wants to ScrewDestiny because he knows his future self [[spoiler: is an EvilOverlord who's [[WorldsStrongestMan powers are so strong]] that ''[[HopeCrusher he destroys anybody's hopes of overthrowing him.]]'' ]]

** [[spoiler:His "fight" against Another Den-O II using Grand Zi-O in #40 is so one sided, it would be generous to even call it a curb stomp.]]

* TheDeterminator: Ever since learning about his future self being a tyrant, Sougo's been doing his damndest to make sure he doesn't go down that path. That being said, if he has to protect his friends, he's more than willing to embark on the road to him becoming Oma Zi-O. [[spoiler:Just ask Another Ryuga, who Sougo demolished with the Zi-O II Ridewatch - the very same Ridewatch that triggered his transformation into Oma Zi-O in the first place.]]

** [[spoiler:It eventually gets so bad that [[GuardianOfTheMultiverse Tsukasa Kadoya]] has to intervene so as to ascertain wether he should destroy the World of Zi-O or not to save the other ones. He has to.]]
* DreamingOfThingsToCome: One of his powers as king is the ability to not only see the future in his dreams, but ''create'' the future by dreaming about it. While Sougo doesn't consciously control the dreams, they're based off his subconscious memories, fears, and desires. It's implied that the entire Geiz Revive arc is the product of Sougo's newfound terror at the thought of becoming Oma Zi-O and wanting to create someone who could kill him. [[spoiler:This gift is used to hide that his so-called "dream" of the man in black was actually a ''memory'' of Swartz abducting him as a child]].
* EveryoneHatesMathematics: Sougo is really bad at math, even needing to take a make up ''of'' a make up exam in #23 and falling asleep whenever he tries to study. [[spoiler:He even falls asleep '''during the exam''' in #24!]]
* FanBoy: #10 reveals that Sougo is one for Oda Nobunaga, the first of the three unifiers of Japan, despite the fact that he was known as a Demon King for his brutal suppression tactics during the Sengoku Era, since the unification of Japan would have be impossible without him. This is also why Sougo don't have a problem about being called a Demon King as well, if Oda could unify Japan despite being a Demon King, than he would just have to be a benevolent Demon King.
* FreakyIsCool: His reaction to the Zi-O Trinity transformation, which is a FusionDance between him, Geiz and Black Woz. Geiz and Woz are turned into wristwatches that merge with Zi-O before his face just falls down to his chest before a new face appears. And all three of them are sharing Sougo's body. His reaction to all this?

* FromNobodyToNightmare: Present day Sougo Tokiwa is little more than a lazy dreamer. Fast-forward to his future self, Oma Zi-O, and he's feared by all.

* GoodIsNotDumb: He may look unassuming, naive and just as far from his future self as he could be. He does have some fairly stupid moments, but otherwise is a scarily good strategist, manipulator and fighter.

* LoveHurts: The entire Kiva arc shows this. Sougo finally gets reunited by chance with Yuko Kitajima, his first love, who gets him to believe she was wrongfully convicted of murder. Turns out she lied; not only did she actually do what she was convicted of, but she's not even the woman Sougo believed she is. However, Sougo is so smitten that she is easily able to trick him. On top of that, she was killed by Ora after her defeat as Another Kiva, right in front of him. Poor dude just needs a hug now.

* NiceGuy: He is polite and friendly to just about everyone, even Geiz (who wants to kill him) and Black Woz (who wants him to become Oma Zi-O). He is actually so polite and optimistic [[CreepyGood it's scary sometime.]]

* RippleEffectProofMemory: Played straight and implied in different instances. During the [[spoiler:Another Zi-O II arc, he's the person other than Woz and the Time Jackers that remembers the original timeline before Hiryu alters it. In the series finale, after Sougo defeated Swartz and undid all the damage he caused, including restoring the timelines of the other Kamen Riders, Sougo ''still'' wishes to become king in spite of the reset he caused as Oma Zi-O]].
* RookieRedRanger: Despite only being recently given his Driver, in his first fight against Geiz who has much more experience as a Kamen Rider which include fighting in a war against his future self and also having more Ridewatches, he still managed to fight evenly against him and even outwit him during their battle and escaped. Later subverted in their second fight, which shows that Sougo didn't so much as get his ass handed to him as he wasn't motivated to fight Geiz at the time.

* ThrowTheDogABone: Book dumb he may be, he finally passed a test for graduation in #24 with a score of 82%.
* TimeMaster: [[spoiler:At first it seemed that his time manipulation powers were the result of Ridewatches, it turns out that Sougo has had these powers at least since he was 10. If anything, the Ridewatches are merely tools to unlock more of ''his'' power rather than bestow anything on him. The powers he has shown are rewinding time, stopping time, rapidly aging something till it turns to dust, predicting a person's future actions, seeing the future in his dreams, even manipulating future timelines and seeing the past. ''Over Quartzer'' reveals that it was actually Swartz who gave him his powers, and SOUGO was the one who stopped the falling debris in #27.]]
* TooPowerfulToLive: Tsukuyomi believes this by #23. [[spoiler:Her seeing Sougo’s ability to reset the timeline reminds her too much of Oma Zi-O that she teams up reluctantly with White Woz. But the realization that Sougo can subconsciously manipulate the future to fit his dreams, deeply terrifies her that she's even more determined to stop him.]]
* TrapIsTheOnlyOption: Being a chessmaster sometimes means Sougo goes for this. Most notably, the reason he makes the seemingly insane decision of following Oma Zi-O's advice to gather all the Ridewatches is because he knows he'll need that level of raw power to take down his future self.

* UnstoppableRage: In the final episode [[spoiler:after Geiz dies protecting Sougo from Swartz, Sougo in his rage and despair unlocks Oma Zi-O's powers. And then it gets worse when Swartz kills Tsukuyomi as well, Sougo screams her name is anguish before he goes on the ultimate RoaringRampageOfRevenge by quickly and brutally killing Swartz with a rider kick.]]

** [[spoiler:Swartz gave Sougo his dream of being a king to gather the Heisei Riders' powers to both strengthen Sougo and cause enough time space distortions that every world except Swartz's is fused into one. Swartz then plans to steal Sougo's power for himself and then destroy Sougo's world to save his world and rule over it as king.]]

* AffablyEvil: For a ruthless tyrant who completely devestated the future, you'd be hardpressed to a situation where Oma Zi-O ''isn't'' being genuinely well-spoken and polite.

* BenevolentBoss: For all the faults he show gives him, he is never seen treating his servant Woz with any disdain in their shared screen time.
* BewareTheSuperman: He is the Overlord of Time who not only has TimeMaster powers, but also wields the power of all 20 Heisei Riders in his disposal [[spoiler:(this now extends to Showa and Reiwa Riders)]] and having brought the entire world to its knees as he rules over the BadFuture with an iron fist. Even to this day, Ohma Zi-O stands out as one of, if not, the most powerful Rider [[spoiler:and ''Kamen Rider'' villain overall]] in existence.

* TheCaligula: When he finally gets more screen-time, it becomes incredibly clear that Oma Zi-O is completely and utterly [[AxCrazy out of his gourd]], genuinely believing that he is "''the greatest and most beloved Demon King''". He's reduced the world of 2068 to a [[Film/MadMax Mad Max lookalike]], has an army of evil monsters at his side that terrorize the populace and slaughters those who resist wholesale. He's [[SarcasmMode clearly a man of the people]].

* TheChessmaster: Seems to be this at the end of ''Forever King 2018''. He knew Sougo would destroy his Driver after seeing how he turned out and FaceDeathWithDignity. When Sougo gains a back-up Driver and reaffirms his desire to not become the Demon King, Oma Zi-O can only laugh as he is ushered back into existence, knowing full well his present-day self would do so. [[CallBack After all, he was born to be king]].

** Evolto wants to destroy earth for fun, Oma Zi-O wants to rule it as the Demon King.

* CurbStompBattle: ''Every single fight'' this man is shown to participate ends in a one-sided slaughter. His introduction seen has him single-handedly wipe out the Resistance. When Sougo attacks his older self, Oma Zi-O doesn't put any effort and simply counters whatever Sougo throws at him by using the same Rider powers he uses. Even when Sougo obtains the Grand Zi-O Ridewatch, he ''still'' mops the floor with his younger self (though compared to their previous bout, Sougo manages to land a few hits on him). [[spoiler:Their third and final rematch subverts this, in that while Oma Zi-O is still superior in terms of power and experiences, [[CurbStompCushion he's hurt by Zi-O Trinity]] [[LoopholeAbuse on account of Trinity being a form he never obtained in his timeline.]] ''[[DoubleSubversion And then it's revealed even that isn't enough to hurt him.]]'']]
* DarkIsEvil: With him, it most ''certainly'' is. The color black is just as prominent as the gold on his suit and this version of our protagonist is an ruthless tyrant who rules over the BadFuture he himself has created.

* DeityOfHumanOrigin: He doesn't come out right out and say it, but in his time, he's become this. Oma Zi-O is functionally omnipotent, unkillable, appeals to the DivineRightOfKings and has the power of twenty generations of heroes or villains in his body. Some of those Riders were never human or were aliens, gods or monsters of staggering power. He can do all that they can and more.

* TheDreaded: Oh, ''most definitely''. When you've managed to kill HALF OF HUMANITY ITSELF before ruling over the rest with an tyrannic iron fist for the next fifty years with no one able to stop you, how can one not qualify as this? It has reached the point that any and all of his most prominent foes who wish to dethrone and/or have him killed had to travel back to ''before'' he even became Zi-O in the first place because his power is ''that'' damn terrifying and overwhelming to directly confront in any capacity. [[spoiler:It's quite telling that the Leader of Quartzer, otherwise known as the ''original Sougo Tokiwa'', also decided on using his younger self, knowing that his plans would most definitely fail if he tried using Oma Zi-O himself to reset the Heisei era.]]
* EvilOldFolks: Given that he is supposed to be Sougo fifty years into the future, he more than qualifies, being in his late sixties. While his face is obscured when his human form is shown, he has white hair and what few details can be made out do imply he's an old man.

* GoneHorriblyRight: SOUGO's goal was to create an alternate version of himself to distract the multiverse from his own machinations. To say this worked too well is something of an understatement, as he created a version of himself whose power VASTLY eclipeses his own, to the point when a portion of it (in the form of modern Sougo's Oma Form) can competely curbstomp him.
* GracefulLoser: [[spoiler:In the final episode as Sougo decides to reverse the damage that Swartz did at the cost of his powers, all Oma Zi-O does is laugh and say that he was glad he got to meet his younger self, before he disappears]].
* HeelFaceTurn: [[spoiler:In the final stageplay (which takes place in the ''Over Quartzer'' timeline), he temporarily gets brought back and joins Sougo for one last battle against Hiryu, who became Another Oma Zi-O. [[CurbStompBattle They completly mop the floor with him.]]]]

* IdentityDenial: An unusual case in that every other character already knows Sougo will grow up to become this tyrant, but Sougo disbelieves that he could ever become such a monster so fervently that he makes Geiz, Tsukuyomi, and even parts of the audience start to doubt it's true, until Sougo's faced with the man himself and can no longer deny reality.
* InvincibleVillain: From Geiz and the Resistance's perspective, as their best efforts were completely crushed by him without doing anything meaningful to him. The only thing that has been shown to be capable of challenging, let alone beating him, is Geiz Revive in White Woz's timeline who battled and defeated Sougo in his Zi-O II form. This ultimately never happens [[spoiler:because it is averted thanks to Geiz and Sougo burying the hatchet]].

* KnightOfCerebus: He's already [[TheDreaded an unstoppable force]] to begin with. The first thing he does in the ColdOpening is to singlehandedly wipe out every member of the LaResistance and going as far as to reduce their army to dust. #16 takes it to a more terrifying level when he beats the Present Sougo using [[Series/KamenRiderKuuga Kuuga]], [[Series/KamenRiderKiva Kiva]], and [[Series/KamenRiderRyuki Ryuki]]'s powers with little to no effort.

** The Oma itself is derived from ''Omagatoki'', a somewhat poetic Japanese term for dusk. More specifically, it refers to the time of day when [[NamesToRunFromReallyFast the world falls into darkness and invites demons and calamity.]]
* MindOverMatter: Has access to every other riders powers, including the kind of telekenisis demonstrated which the likes of Kouta would be capable of.

* PhysicalGod: By the time he rules the world, he has fully mastered his power which include willful manipulation of time and space combined with the entire powerset of the Heisei riders. He demonstrates some of Kuuga's and Kiva's abilities combined with enough raw power to one shot some of the strongest rider villains. WordOfGod confirms he had powers he hasn't openly demonstrated: like Kouta's reality warping, Evol's planetary destruction and galactic warping, Cronus' Pause, Genm's resurrective immortality, various riders' super speed etc. etc. and he is literally all powerful. The finale and supplementary information goes even further, revealing the power to sense people in other dimensions, fight with infinite energy coursing through his body, teleport through space and time, age objects to death, manipulate fate, and destroy all of space and time within the Kamen Rider multiverse.

* PuppetKing: Shortly after he is ushered back into existence and begins to laugh, believing that everything is going as he has expected, a shadow is sitting behind Oma Zi-O's throne, hinting that for all his power Oma Zi-O may be subservient to someone else. [[spoiler:This is downplayed as #27 and #28 reveals that Sougo is Swartz's candidate for Oma Zi-O, but later episodes show that the existence of Oma Zi-O means that Swartz's plan failed. And ''Over Quartzer'' reveals that he's also this to ''his own alternate self'' before he helped his younger self defeat his alternative self.]]
* RapidAging: Combined with OneHitKill, one of the powers he shows in #1 when he was able turn an entire army to dust.

* ScarfOfAsskicking: He has a pair of watch hands hanging down the back of his suit, which either gives of this or BadassCape.

** As befitting for an evil version of the anniversary Kamen Rider, he's this to every main Heisei series Rider that came before Zi-O. In [[Series/KamenRiderKuuga Kuuga]], [[Series/KamenRiderBlade Blade]], [[Series/KamenRiderGaim Gaim]], and among others, one big concern and theme running throughout each story was what [[BewareTheSuperman amassing enough power to reach their full potential]] would do to their minds and [[HeWhoFightsMonsters turn them into the very thing they were fighting against]]. Kuuga feared becoming a LivingWeapon who lived only for fighting, Blade was worried he'd turn into a monster like the Undead he's trying to defeat, and Gaim was afraid of giving up his humanity the stronger he got. This version of Sougo is what happens when all of that power goes to one's head and he becomes a tyrant worse than any villain in the Heisei era.
* SpannerInTheWorks: [[spoiler:Over Quartzer's plan was actually going quite well and was close to succeeding...until Oma Zi-O decided enough was enough and proceeded endow his younger self with enough of his power to defeat SOUGO and lead Woz into pulling a HeelFaceTurn]].

* TautologicalTemplar: The man somehow believes that he honestly is the "''the greatest and most beloved Demon King''". Despite the fact that he killed half of the population of earth, put the other half in ghetto camps, and periodically terrorizes said survivors with his army. The most twisted thing about him is the fact that [[MetaphoricallyTrue from a certain point of view]] he ''is''. After all, [[OverlyNarrowSuperlative he's the only Demon King the world's ever had]], and from his warped perspective he's simply putting down insurrections against his "benevolent" rule.

* UsedToBeASweetKid: The Sougo we're following is an AllLovingHero that wants to become king to protect the people around him. This Sougo is no longer anything like that.

* AllYourPowersCombined: Zi-O Trinity, Grand Zi-O, Zi-O Oma Form and Oma Zi-O are all built on this trope.

* BoringButPractical: Zi-O Trinity lacks the CombatClairvoyance of Zi-O II, monstrous speed of Geiz Revive, or various special abilities of Woz's Miridewatches and the Rider Armors, trading it all for a substantial increase in brute strength and access to their various weapons. [[spoiler:And it has the secret bonus of being able to hurt Oma Zi-O, as it never existed in his own timeline.]]

** The Zikan Gilade gets in on this too, where the side of the weapon's current form having the katakana for either "sword" or "gun"

* CanonWelding: [[spoiler:Oma Form's summoning abilities are essentially Grand Zi-O's with this on top of them. While Grand Zi-O can summon the riders from any point in time, Oma Form can summon any rider from any form of Kamen Rider continuity, such as web-series, manga adaptations, and even stageshows.]]

* CombatClairvoyance: Zi-O II gives Sougo the ability to see his opponent's future moves, via the Precedence Blades atop his helmet. The ability isn't an instant-win button on its own, though: an opponent whose reflexes are too fast can react to Sougo's predictions, while other foes are simply too strong. In both cases, while the clairvoyance helps, Sougo also needs to outwit his opponents the old-fashioned way.
* DarkIsNotEvil: Another black colored Rider, but Sougo is deadset on ensuring that this trope is in effect. When told that he'll become a Demon King, he resolves to become "the greatest, kindest Demon King ever!" [[spoiler:This is even true in the final episode when Sougo becomes Oma Zi-O but proves to be as benevolent as before.]]

** '''Time Break''': A series of magenta colored characters that spell out "Kick" circle around Zi-O's opponent, and when he jumps up, they land on his right foot as he lands a jump kick.

** '''Limit Time Break''': In [=FourzeArmor=], Zi-O transforms into a rocket-like state to fly himself and the enemy into the Earth's upper atmosphere before delivering a corkscrew kick with his lower half covered in magenta energy. This is referred to as the Space Rocket Tailspin Kick. Alternately, he can skip the "space" step and just perform a corkscrew kick, known as the Rocket Tailspin Kick.

** '''Squash Time Break''': In [=GaimArmor=], Zi-O charges the Daidaimaru Zs with energy before unleashing a powerful slash on the target that traps them in an badly drawn orange sphere. Alternatively, he can slash at his opponents, and break them into pieces.

** '''Maximum Time Break''': In [=WArmor=], the Rider Armor assume their Memory Droid forms representing Double's halves, with all three converging on the target in a rider kick similar to the Triple Extreme.

** '''All Twenty Time Break''': In Grand Zi-O form, he summons as many of the main Heisei Riders and have them perform their final attacks on the opponent. He could opt to freeze them temporarily to deal some strikes to the enemy beforehand. Alternatively, he can just summon ''all'' of the main Heisei Riders and perform a combined Rider Kick.
** '''Oma Zi-O Hissatsu-Geki'''[[note]]Lit. Calamity Time King Deadly Strike[[/note]]: In Oma Zi-O form, Zi-O channels energy then jumps high to perform a Rider Kick, while a series of black-colored "Kick" characters appear and circle the enemy. The Apocalypse of Kingdom moves into V-shape when Zi-O performing attack.

** '''Ultimate Time Break''': After plugging the Decade Ridewatch into the Heisaber, and selecting all 19 of the previous 19 Heisei Riders symbols with the Hand Selector, Zi-O creates several cards-like projections, before delivering several Rainbow-energy coated slashes to enemy. When in Decade-Ex-Aid Armor, the strike is delayed for a bit before taking effect, reminiscent of Ex-Aid's Hyper Muteki finisher ''Hyper Critical Sparking''. When the Ryuki Ridewatch is plugged in, Zi-O coats the blade in orange flaming vortex before launching it at the enemy.

* GoodCounterpart: Sougo's Super Mode Grand Zi-O is this to his future self's Oma Zi-O form. They are both the result of Sougo gaining the powers of all the main Riders of the Heisei era, have a regal design and has gold as the primary color of the form. [[spoiler:Subverted as Grand Zi-O is less a good counterpart and more a vastly incomplete version of Oma Zi-O as it only has the powers of the main 20. This is also played straight with Sougo's Oma Form, possessing the Oma Zi-O Ridewatch from his future self that gives him the powers of Oma Zi-O that doesn't corrupt him.]]
* HowDoIShotWeb: Despite inheriting the powers of other Riders, he doesn't really know much about them or how they fight, at best being able to briefly see them in action when travelling back in time. This often leads to situations like flubbing Build's catchphrase or performing Fourze's ''Rider Rocket Drill Kick''... By [[ExactWords transforming into a rocket and corkscrewing through space feet-first into his opponent.]]
* HumongousMecha: Zi-O has a Time Mazine (originally Tsukuyomi's) to use for time travelling to the past, and battling against the Time Jacker's own Time Mazines. Additionally, the Time Mazine can also utilize a few of the Ridewatches powers when Zi-O plugs them into his Ziku Driver (for example: when using the OOO Ridewatch, the Time Mazine inherits's OOO's Tora claws).

** Zi-O Trinity's greatest strength is also its greatest weakness. While the form is very powerful due to fusing Zi-O, Geiz and Woz into one, allowing them to steamroll pretty much everyone else but if they ever face someone stronger than them, [[spoiler:like Kamen Rider Ginga,]] it becomes nearly impossible to fight intelligently because Sougo, Geiz and Woz are bickering over what to do.
** [[spoiler:Grand Zi-O might have the power of all 20 main Heisei Riders but Sougo needs to touch their respective relief to use their powers. Thus if he's outnumbered he can't use their powers as shown when Another Zi-O II and Another Decade can summon their respective never dying Another Riders and Another World Dark Riders to overwhelm him. Also Sougo can only use the maximum strength of the Riders in their canon thus if they face enemies stronger than them like how Another Decade's Another World Dark Riders are, they will inevitably be destroyed and Sougo overwhelmed as well.]]
* MidseasonUpgrade: He gets two, the Decade Ridewatch and Zi-O II. Decade provides an interesting spin since it gives him access to the other Heisei Riders' Midseason Upgrades like Build [=RabbitTank=] Sparkling or OOO Tajador Combo; for Riders without mid-season forms he instead assumes their final forms, such as Ryuki Survive.

** '''[=FourzeArmor=]''': Gains access to Fourze's powers, wields two Booster Modules on his arms, and can transform into a rocket himself.

** '''[=GhostArmor=]''': Gains the abilities of Kamen Rider Ghost, such as invisibility, intangibility and is capable of levitation at will. He can also summon Parka Ghosts as reinforcements through the Eyecon Shoulders. This armor is primarily used by Geiz.

** '''[=KuugaArmor=]''': Gain's Kuuga's hand to hand combat skills, similar to the Mighty Form.

** '''[=Grand Zi-O=]''': Gains the powers of all 20 main Heisei Kamen Riders. By tapping a statue once, he can create a time portal to summon that specific Rider from their timeline. Tapping it twice summons their weapon. Tapping his own statue can make all the Riders he summoned freeze in time, regardless of whenever they're midair or not.

** '''[=Oma Zi-O=]''': Combines the powers of every Heisei Rider, primary or not, into a single body. This allows him to not only summon the Riders in a similar fashion to Grand Zi-O but manifest their abilities himself without need to summon them.

* SuperMode: Kamen Rider [=GrandZi-O=], his final form accessed with the [=GrandZi-O=] Ridewatch. It wields the power of all 20 Heisei Kamen Riders. He contains statues of all of the Heisei Kamen Riders adorned on his body with Zi-O's making a crown. He can summon any version of all 20 primary rider by tapping the corresponding statue.[[spoiler:His extra final forms, Oma Form gives him powers of Oma Zi-O and then there's the actual Oma Zi-O he becomes ..]]
* TemporalParadox: Trinity and Grand are two forms that do not exist in Oma Zi-O's timeline. Even if Sougo was to ultimately follow his future self's path, the timeline has been fundamentally altered.

** Sougo as Zi-O is the inverse of [[Series/KamenRiderDecade Tsukasa Kadoya]] in many aspects: both are anniversary Riders who deal with threats to all of the Kamen Rider multiverse - threats stemming from their own actions from their time as nearly all-powerful villains. Both are {{{Guile Hero}}es who [[PoorCommunicationKills cause tension with their allies as a result of their manipulations]]. Tsukasa's villainy was in the past, with him becoming a JerkWithAHeartOfGold, whereas Sougo's is in the future while he is currently a {{Cloudcuckoolander}}. Tsukasa met AlternateUniverse versions of the other Riders, while Sougo meets the genuine articles but unintentionally corrupts them into alternate versions of themselves through his actions. Tsukasa was portrayed in his show as the most powerful Kamen Rider of all, and acted as a mentor who imparts lessons to the AR Riders that he meets, while Sougo is outclassed as a fighter and a hero by most of the other Riders that he encounters, and spends the show learning and growing from what they have to teach him.

** Sougo as Zi-O is the inverse of Tsukasa Kadoya/Series/KamenRiderDecade in many aspects: both are anniversary Riders who deal with threats to all of the Kamen Rider multiverse - threats stemming from their own actions from their time as nearly all-powerful villains. Both are [[GuileHero Guile Heroes]] who [[PoorCommunicationKills cause tension with their allies as a result of their manipulations]]. Tsukasa's villainy was in the past, with him becoming a JerkWithAHeartOfGold, whereas Sougo's is in the future while he is currently a CloudCuckoolander. Tsukasa met AlternateUniverse versions of the other Riders, while Sougo meets the genuine articles but unintentionally corrupts them into alternate versions of themselves through his actions. Tsukasa was portrayed in his show as the most powerful Kamen Rider of all, and acted as a mentor who imparts lessons to the AR Riders that he meets, while Sougo is outclassed as a fighter and a hero by most of the other Riders that he encounters, and spends the show learning and growing from what they have to teach him.

** As befitting for evil version of the anniversary Kamen Rider, he's this to every main Heisei series Rider that came before Zi-O. In [[Series/KamenRiderKuuga Kuuga]], [[Series/KamenRiderBlade Blade]], [[Series/KamenRiderGaim Gaim]], and among others, one big concern and theme running throughout each story was what [[BewareTheSuperman amassing enough power to reach their full potential]] would do to their minds and [[HeWhoFightsMonsters turn them into the very thing they were fighting against]]. Kuuga feared becoming a LivingWeapon who lived only for fighting, Blade was worried he'd turn into a monster like the Undead he's trying to defeat, and Gaim was afraid of giving up his humanity the stronger he got. This version of Sougo is what happens when all of that power goes to one's head and he becomes a tyrant worse than any villain in the Heisei era.

* PhysicalGod: By the time he rules the world, he has fully mastered his power which include willful manipulation of time and space combined with the entire powerset of the Heisei riders. He demonstrates some of Kuuga's and Kiva's abilities combined with enough raw power to one shot some of the strongest rider villains. WordOfGod confirms he had powers he hasn't openly demonstrated: like Kouta's reality warping, Evol's planetary destruction and galactic warping, Cronus' Pause, Genm's resurective immortality, various riders' super speed etc. etc. and he is literally all powerful. The finale and supplementary information goes even further, revealing the power to sense people in other dimensions, fight with infinite energy coursing through his body, teleport through space and time, age objects to death, manipulate fate, and destroy all of space and time within the Kamen Rider multiverse.

* PhysicalGod: By the time he rules the world, he has fully mastered his power which include willful manaipulation of time and space combined with the entire powerset of the Heisei riders. He demonstrates some of Kuuga's and Kiva's abilities combined with enough raw power to one shot some of the strongest rider villains. WordOfGod confirms he had powers he hasn't openly demonstrated: like Kouta's reality warping, Evol's planetary destruction and galactic warping, Cronus' Pause, Genm's resurective immortality, various riders' super speed etc. etc. and he is literally all powerful. The finale and supplementary information goes even further, revealing the power to sense people in other dimensions, fight with infinite energy coursing through his body, teleport through space and time, age objects to death, manipulate fate, and destroy all of space and time within the Kamen Rider multiverse.

* MeaningfulEcho: When Sougo meets him for the first time, he reaffirms his desire to become the world's greatest and most beloved demon king...only for Oma Zi-O to throw those words back at him, stating he ''is'' the greatest and most beloved demon king. That his older self genuinely believes this while ruling over a dystopian future is what makes Sougo realize how utterly warped he'' become and actually makes him go through a TenMinuteRetirement.

* WorldsStrongestMan: Possessing the combined powers of not just Heisei Riders, but '''ALL''' riders (Including ''Showa'' and ''Reiwa''), Oma Zi-O is bar none '''''THE''''' most powerful being in ''Kamen Rider'' lore. The one and only time he's seen truly fighting seriously, he obliterates the likes of [[PlanetEater Evolto]], [[PhysicalGod Gamedeus]], and [[PersonOfMassDestruction N-Daguva-Zeba]] [[OneHitKill in a single blow each]]. In the ''Zi-O Vs. Decade'' finale, [[spoiler:during a state in which a incarnation of him is at his weakest, he still manages to overpower Decade Complete 21, the upgraded version of [[SuperMode Decade Complete form]].]]

!!!'''Portrayed by:''' So Okuno (live), Seiji Takaiwa (suit)\\

* BewareTheSuperman: He is the Overlord of Time who not only has TimeMaster powers, but also wields the power of all 20 Heisei Riders in his disposal [[spoiler:(this now extends to Showa and Reiwa Riders)]] and having brought the entire world to its knees as he rules over the BadFuture with an iron fist. Even to this day, Ohma Zi-O stands out as one of, if not, the most powerful Rider [[spoiler:and ''Kamen Rider'' villain overall, superseding Evolto]] in existence.

* BewareTheSuperman: He is the Overlord of Time who not only has TimeMaster powers, but also wields the power of all 20 Heisei Riders in his disposal [[spoiler:(this now extends to Showa and Reiwa Riders)]] and having brought the entire world to its knees as he rules over the BadFuture with an iron fist. Even to this day, Ohma Zi-O stands out as one of, if not, the most powerful Rider [[spoiler:(and ''Kamen Rider'' villain overall, superseding Evolto)]] in existence.

* BewareTheSuperman: He is the Overlord of Time who not only has TimeMaster powers, but also wields the power of all 20 Heisei Riders in his disposal and having brought the entire world to its knees as he rules over the BadFuture with an iron fist. Even to this day, Ohma Zi-O stands out as one of, if not, the most powerful Rider [[spoiler:(and ''Kamen Rider'' villain overall, superseding Evolto)]] in existence.

* BewareTheSuperman: He is the Overlord of Time who not only has TimeMaster powers, but also wields the power of all 20 Heisei Riders in his disposal and having brought the entire world to its knees as he rules over the BadFuture with an iron fist. Even to this day, Ohma Zi-O stands out as one of, if not, the most powerful Rider [[spoiler:(and ''Kamen Rider villain'' overall, superseding Evolto)]] in existence.

** As befitting for evil version of the anniversary Kamen Rider, he's this to every main Heisei series Rider that came before Zi-O. In [[Series/KamenRiderKuuga Kuuga]], [[Series/KamenRiderBlade Blade]], [[Series/KamenRiderGaim Gaim]], and among others, one big concern and theme running throughout each story was what amassing enough power to reach their full potential would do to their minds and [[HeWhoFightsMonsters turn them into the very thing they were fighting against]]. Kuuga feared becoming a LivingWeapon who lived only for fighting, Blade was worried he'd turn into a monster like the Undead he's trying to defeat, and Gaim was afraid of giving up his humanity the stronger he got. This version of Sougo is what happens when all of that power goes to one's head and he becomes a tyrant worse than any villain in the Heisei era.

* WorldsStrongestMan: [[spoiler:As Oma Zi-O, he combines the powers of every single Heisei Rider into one body, making him strong enough to slaughter an entire army of monsters within seconds, defeat previous final bosses with a single blow each and remake the entire Kamen Rider multiverse to suit his whims.]]