- Written by: Nobuhiro MouriDirected By: Takayuki Shibasaki
He has inherited the power of all Riders and become Grand Zi-O.
However, it seems that what awaited him was a world where history had been greatly altered...
The fight of Oma Zi-O against Grand Zi-O is raging on as they attack each other fiercely. Grand Zi-O summons Kamen Rider Build to fight for him, as Oma Zi-O summons Kamen Rider Kuuga. The summoned riders defeat each other with their rider kicks, so Grand Zi-O summons Kamen Rider Drive. But, Oma Zi-O assumes control of Drive instead, and his SpeeDrop finisher defeats Grand Zi-O.As Woz arrives to help Sougo, the Demon King explains that Sougo cannot defeat him as he is yet to collect all of the Heisei Riders' power. Woz realizes that the Drive Ridewatch inside Grand Zi-O Ridewatch was stolen by Geiz from Oma Zi-O, so the power of Grand Zi-O isn't complete yet. Oma Zi-O then proceeds to blast Sougo, but Woz saves him inside his scarf. As the Demon King praises Woz for a job well done, a history-changing wave approaches them...
Sougo awakens in an unknown place. He walks around and learns that this is indeed the year 2019, so he has returned to the present. Unbeknownst to him, Tsukasa Kadoya is watching from afar, stating that this is the end of Zi-O's world. As battle wages around him, Sougo comes across a statue of Hiryu Kakogawa, surrounded by Another Riders. On the placard it reads, "The Commemoration of Hiryu Kakogawa's Transformation."
A panicked Sougo goes to his house, but much to his surprise, the 95 DO is transformed into a shelter for wounded civilians. As he ponders around, Junichiro attacks him with a daikon radish out of nowhere. Sougo eludes him and before he can ask for more information, Tsukuyomi's voice is heard from a comm device, requesting help because Another Riders are attacking a shelter. Sougo hurriedly goes to help her, as Junichiro wonders who the young man is.
Geiz and Tsukuyomi are fending off Another OOO and Another Kiva as Sougo arrives. After helping Tsukuyomi, Sougo transforms into Zi-O II. Geiz and Tsukuyomi recognize him as the "Great Demon King" Zi-O, thus they attack Sougo. As Sougo doesn't want to fight his friends and is confused about this turn of events, he loses badly. Just then, Time Jacker Heure appears and saves Sougo with his time stopping power. Sougo escapes and Geiz angrily states that it is his dearest wish to kill Zi-O with his own hands.
In a building, Heure arrives before Swartz and Ora. He says that he's done saving Sougo, as per Swartz's command to let Zi-O live. Ora explains as Sougo already got his greatest power as Grand Zi-O, Swartz resorts to a desperate measure, to raise a new king candidate with powers on the level of Grand Zi-O. Swartz then commands Ora to accompany the new king candidate, and she grudgingly goes, muttering that they're supposedly in equal positions as Time Jackers.
As Sougo is moping beside a devastated pond, Woz arrives beside him. Sougo states his confusion about this turn of events, but Woz apparently knows more about it. Suddenly Ora appears with her new king candidate... Hiryu Kakogawa. Woz leaves Sougo's side as his future as Demon King has disappeared from his book, thus he should now serve Hiryuu.
Hiryuu explains that he used his newfound power to become the new Demon King. He did it because Sougo defeated and humiliated him before, so he swore to ruin Sougo's life. An angered Sougo transforms into Grand Zi-O while Hiryuu transforms into Another Zi-O II, and they clash. Meanwhile, Heure informs Geiz and Tsukuyomi of Zi-O's whereabouts.
Another Zi-O II has ability similar to Grand Zi-O, in which he can summon Another Riders to his bidding. He summons Another Den-O, Another Gaim and Another Agito as Grand Zi-O summons their true counterparts. The true riders defeat their Anothers, but Hiryuu demonstrates his other power: that of changing history. By changing history, he ensures that the Another Rider's defeat never came to pass, and the newly revived Another Riders defeat their true counterparts. They move to attack Sougo, and he defeats them using King Girigiri Slash... only for Another Zi-O II to change history once again. In the end, Sougo is defeated.
Luckily, Tsukasa Kadoya saves Sougo with a machine gun and leads him out of battle. Once they're safe in an underground parking lot, Tsukasa asks his junior rider about his desire to be a king. Sougo answers that his desire is meaningless now as Geiz, Tsukuyomi and Woz are leaving his side. An annoyed Tsukasa lifts him up, asking if Sougo wanted to become king just for his companions. He didn't; Geiz, Tsukuyomi and Woz came to Sougo BECAUSE he wants to be a king- not the reverse. Tsukasa drops him and says that he will help, but not before he defeats the roaming Another Riders.
As Another Den-O, Another Gaim and Another Agito chase him, Sougo transforms into Grand Zi-O once more. But now he doesn't summon true Kamen Riders to deal with them, he only summons Den-O's Den-Gasher and Gaim's Daidaimaru to defeat Another Den-O and Another Gaim respectively, then "summons" Agito's skill to defeat Another Agito. As Another Zi-O II isn't present for this battle, the Another Riders remain defeated. As Sougo revels in his victory, Geiz arrives and challenges him to battle...
Tropes:
- Armor-Piercing Question: When Sougo questions if he can even beat Hiryu as Another Zi-O II without the support of Geiz, Tsukuyomi, and Woz, Tsukasa questions Sougo if his desire to become king is still genuine since Sougo has misunderstood why the 2068 time travelers came to him in the first place.
- Attack Backfire: When Grand Zi-O summons Kamen Rider Drive to attack Oma Zi-O, the latter is able to control him into defeating Grand Zi-O instead. This is because Sougo has not personally obtained the Drive Ridewatch, the one used to create the Grand Zi-O Ridewatch having come from Geiz taking it from Oma Zi-O.
- Be Careful What You Wish For: Ever since Sougo learned what a maniac his future self is, he's done his best to not become Oma Zi-O and in this episode due to the Ret-Gone he is no longer destined to be Oma Zi-O. But instead Hiryu has become the Overlord in his place and is currently destroying the world that Sougo sought to protect all the while his friends and family have forgotten about him and thus are hostile.
- Big Damn Heroes: Tsukasa saves Sougo from being overwhelmed by Another Zi-O II and his Another Riders.
- Early-Bird Cameo: If one looks closely when looking at Hiryu's statue surrounded by the Another Riders, one can make out Another Drive (a warped head spoiler, pointed shoulder pads, and cybernetic parts) and Another Decade (black gauntlets, shoulder with lined protrusions, and part of Decade's "X") from the backside.
- Fake Defector: Due to the timeline changes in the present time, Woz pretends to pull a Face–Heel Turn in order to align himself with Hiryu and the Time Jackers as part of his undercover.
- Foreshadowing: With Freeze-Frame Bonus. Another Drive and Another Decade's statues can be seen at the back of the silver statue of Hiryu Kakogawa.
- From Bad to Worse: Hiryu as Another Zi-O had demonstrated his ability to create a legion of Another Riders the last time he appeared, but as Another Zi-O II, he is able to create them from thought alone without visibly using any Anotherwatches or hosts. And then there are the facts that his power has grown to the point that he can rewrite history at will (which includes undoing his Another Riders' losses when he can see them) and can match GrandZi-O in pure strength.
- Heroic BSoD: Sougo goes through a massive one after losing to Hiryu with addition of his uncle, Geiz and Tsukuyomi not remembering him in the alternate 2019.
- Imperfect Ritual: Despite having the Grand Zi-O Ridewatch, Sougo is unable to fight Oma Zi-O on even ground as he has yet to obtain the Drive Ridewatch, or rather, not the one from his timeline.
- In Spite of a Nail: Despite Sougo never existing, Geiz was still able to gain the Geiz Revive Ridewatch.
- Mistaken Identity: Despite the fact that Hiryu was the one depicted to become Oma Zi-O in the new timeline, upon seeing Sougo transform into Zi-O II, Geiz and Tsukuyomi immediately assume Sougo is the Oma Zi-O they need to defeat. Geiz in particular even refuses to let Sougo explain himself and goes all-out in trying to kill him.
- Redemption Rejection: It's revealed that Hiryu turned down Sougo's advice to live for the present instead of holding onto grudges of the past, considering it an insult.
- Ret-Gone: After Oma Zi-O defeats Sougo and Woz sends him back to the present, time is changed so Sougo never existed and thus Junichiro, Geiz and Tsukuyomi have no idea who he is, with Hiryu taking his place as the future Oma Zi-O.
- Ripple-Proof Memory: Despite Sougo being erased from time, the Time Jackers, Woz, Hiryu and Tsukasa still remember him.
- Took a Level in Badass: As a result of Sougo being Ret-Gone, Hiryu became Another Zi-O II with powers equal to Grand Zi-O.
- Took a Level in Jerkass: More accurately Geiz lost his Took a Level in Kindness due to his memories of Sougo being erased and is back to the Black-and-White Insanity Well-Intentioned Extremist he was at the start of the show. The same goes to Tsukuyomi, as her hostility towards Sougo resurfaces again to the point of attacking him.
- Villainous Rescue: Before Geiz Revive could kill an untransformed Sougo in their first encounter in the new timeline, Heure freezes time so that Sougo could escape. He only did that just to make Zi-O suffer more.
- Worf Effect: Hiryu, as Another Zi-O II, is able to beat Sougo in Grand Zi-O form.
