Over the past 20 years the Kamen Riders have battled against the likes of the Grongi, Unknown, Fangire, Orphnoch, Greeed and so many more. They’ve been doctors, demon hunters, wizards and detectives. Some have journeyed through the decade and travelled through time, while others hail from parallel universes. But eventually all things come to an end, and as the curtain closes on the Heisei era a new one is about to begin. But before welcoming the Reiwa era with Kamen Rider Zero-One, Toei celebrated the longest consecutively-running period in Rider history with Kamen Rider Zi-O. As the 20th and final Heisei series Zi-O pays tribute to everything from Kamen Rider Kuuga all the way up to Kamen Rider Build, with plenty of guest stars and surprise developments to see the era off in style.In the year 2018 Sougo Tokiwa is just a high school student who dreams of becoming a king. But fifty years into the future he will become Ohma Zi-O – the demon ruler of time who has harnessed the power of all Kamen Riders. When resistance fighters Tsukuyomi and Geiz Myokoin travel into the past attempting to prevent this apocalyptic future, Sougo is determined to become a benevolent ruler and prove his destiny isn’t set in stone.As a group known as the Time Jackers unleash monstrous “Another Riders” across time in an attempt to alter the history of the Heisei Riders, Sougo battles to save the time space continuum as Kamen Rider Zi-O. Aided by Tsukuyomi and Geiz as well as his future retainer Woz, Sougo meets the Riders of the past – gathering their powers while also creating a new future without the threat of Ohma Zi-O.The mantle of an anniversary series comes with certain expectations, and when said anniversary is the swan song to a whole era there’s a lot of pressure to do something big. And Kamen Rider Zi-O is a series not afraid to dream big. Right from the get go it offers a time travelling plot line, bringing back past Riders as the events of their shows became entangled in Zi-O’s own story. But it wasn’t plain sailing from the start, and tackling time travel always presents problems. Initially Zi-O proved divisive as it played fast and loose with Rider continuity, while at the same time setting rather strict rules its own story had to play by. Issues like how the Another Riders come into existence and how they’re destroyed had explanations, others such as why Sento Kiryu in a world without Kamen Rider Build would still be Sento Kiryu did not. As enjoyable as Zi-O could be, it said a lot that its plot holes were often the butt of jokes in comedic webisodes.These early teething problems are no fault of the cast though, who all settle into their roles quickly and develop nicely over the course of the series. So Okuno brings a youthful charm to Sougo, brilliantly painting him as heroic and optimistic, firm in his dream no matter how delusional it seems. These qualities make him the perfect for both interacting with and leaving an impression on others, as well as leaving the viewer curious to see just how this boy could ever become the ruthless Ohma Zi-O. Sougo has the perfect foil in the stubborn and battle-hardened Geiz, and although Gaku Oshida’s portrayal can be (understandably given the context) irritating in his obstinance, Geiz’s growing trust in Sougo over the course of the series is among its stronger character moments. Tsukuyomi (played by Shieri Ohata) on the other hand is disappointingly short changed in how active her role is, though later plot revelations do try to make up for this. Finally there’s Woz, who strikes a fine line between comedy and moral ambiguity in his fanaticism of his overlord. Not to mention Keisuke Watanabe playing two different versions of him came completely out of left-field, and he does a fine job of it too.Unfortunately the same high praise can’t be said of the villains. Not that any of them are especially bad by any means, more that plot seems content to keep them shrouded in mystery. Despite boasting some really strong appearances the over-looming presence of Ohma Zi-O remains more of a threat than a promise, so rarely does it feel like the Sougo we follow could become this tyrant. Similarly the Time Jackers are a constant presence yet their motivation and background is barely a footnote, until the story sheds some light on just one of them at the very end. It’s not that they’re bad characters, more that after several years of engaging and/or multi-layered villains they just seem very one-note.However when Zi-O finally lets go of all the rules it initially imposed upon itself, it becomes a cleverer and far more enjoyable series. The introduction of a series of “Future” Riders hailing from an altered timeline is an unexpected move for something which logically should be preoccupied with celebrating the past, but it offered the chance for a different kind of guest star as well as a reminder that Kamen Rider should always be looking toward the future. While Kamen Riders Shinobi, Quiz and Kikai will never get their own series, it’s fun to speculate on what they could have been as we inch closer to the beginning of Zero-One.The fact this change roughly times with Tsukasa Kadoya’s arrival as a reoccurring cast member as opposed to a one-off guest can’t be a coincidence. Like Zi-O, Kamen Rider Decade also tried to go big with its ideas on how to celebrate an anniversary – perhaps even more so as it attempted to do it with alternate universe Riders rather than the real deal. But while it’s generally agreed that Decade’s story failed to live up to its promises, it still manages to stand out thanks to the strength of its cast and the sheer spectacle of its more memorable moments. At this point it feels like Zi-O tries to follow a similar path, as issues like past Riders being erased by the creation of Another Rider or the cost of Geiz using his Revive form are either hand waved away or just outright forgotten. Bigger things like just who the hell Kamen Rider Ginga is don’t even matter. Rider continuity is brought into question once again with the late game revelation that each series takes place in its own world, which in itself highlights how much of a frustrating mess Zi-O is if you sit down and try to think about it too hard. But sit back, just accept what you see on screen and the show becomes a non-stop thrill ride that wastes no opportunity to celebrate the Heisei era in a variety of interesting ways.Whereas in the first half merging the Fourze and Faiz episodes to make a funny little number pun was about as clever as the tributes got (depending on how you feel about an OOO tribute essentially being turned into the Kuroto Dan show that is), the second half takes a deep dive into each shows’ respective histories to make them truly exciting for fans. Both Blade and Hibiki get continuations that either redeem past mistakes or offer closure, while the Kabuto arc finally gives Arata Kagami the moment he’s always deserved. Meanwhile the Agito arc presents a neat spin on the Another Rider concept, and the loud out loud fun of the Imagin returning in the Den-O episodes is just further evidence as to why that show got so many sequels and spin-offs. Many of these tributes come complete with the shows’ original insert music to make them feel all the more complete.Then of course there’s the cameos. With the exception of Kuuga there is representation from all 19 of the previous Heisei series, some much more significant than others (Fourze and Kiva fans should also prepare for disappointment). In many of the cases where the lead character was unavailable the show does its best to bring back someone that will resonate with the fandom, and as it approaches its endgame these cameos become all the more unexpected and exciting. No one truly expected to see Kamen Rider Aqua from Movie Wars Megamax again, let alone in a multi-part story arc that would see him face off against Kamen Rider Eternal. It might not be quite on something like Gokaiger’s level when it comes to scale, but when add up the numbers and it certainly isn’t that far off. But once again leading this charge is Tsukasa, with Masahiro Inoue completely stealing the show like he never left the franchise. Whether you love it or loathe it there’s no denying that Kamen Rider Decade was a troubled production, so it’s amazing to have him (along with Daiki Kaito/Kamen Rider Diend) back to continue their story. Of course in traditional Decade fashion his appearance and new powers raise all sorts of questions, none of which are likely to ever be answered. But Decade somehow manages to be that one area in the franchise where it never really matters, and that’s all down to just how good Inoue is in the role.The visual side of things also live up to the expectations of an anniversary series, with plenty of older suits (some in better condition that others) being brought out of the Toei store cupboard for a range of varied and exciting action scenes. The base suits for Zi-O, Geiz and Woz are all wonderfully designed with their different watch aesthetic and unique “Rider” eye pieces, with subsequent upgrades taking them all in different directions. Kamen Rider gaudiness reaches a new level with Grand Zi-O – covered head to toe in gold busts of each Heisei Rider along with a nearly two-minute belt jingle encompassing all of their individual sounds. Though they never get through all 19 in the show itself the Ride Armours are another really fun concept, and like how the shows themselves have evolved over the years the designs vary from restrained to outright ridiculous. The way the design team were able to take pieces of older suits and repurpose them into four unique-looking “future” Riders just highlights the level of ingenuity the design team had working on this show. But when it comes to design alone the real winners of the series are of course the Another Riders. The Ayakashi Diend from Decade’s Shinkenger crossover was far too good of an idea to only use once, so Zi-O bringing it back to produce monster equivalents to every Heisei Rider as well as the new future Riders really is a delight. As well as the sheer level of detail that went into each suit they all have their own individual quirks, many of which pervert those of the original Riders in subtle ways. The Another Riders are so good that it’s not only hard to pick a favourite, but also to pick a least favourite.Though it may often struggle with the logistics and consistency of its lofty story, Kamen Rider Zi-O is a highly enjoyable series that excels where it truly counts – as a true celebration of the Heisei era. With only a few omissions to speak of nearly every series from the past 20 years is properly celebrated in some way – be it through guest appearances, clever call backs or even continuations that build upon established continuity. A true love for all things Kamen Rider shines throughout the show, and because of that even in its weaker moments it’s hard not watch with a huge grin on your face. As the last time fans may see some of these characters in any significant capacity, Kamen Rider Zi-O is a goodbye worth savouring.