Rider Time: Kamen Rider Decade VS Zi-O -Decade's Mansion Death Game-

Rider Time: Kamen Rider Decade VS Zi-O -Decade Mansion's Death Game- (RIDER TIME 仮面ライダーディケイド VS ジオウ -ディケイド館のデス・ゲーム- Raida Taimu: Kamen Raidā Dikeido Tai Ji-Ō -Dikeido-Kan no Desu Gēmu-) is the third installment of the Kamen Rider Zi-O Spin-off series that focuses on Tsukasa Kadoya/Kamen Rider Decade.

Why It Sucks

 * 1) The Concept of the Spin-off is really terrible and it's a rip-off of Kamen Rider Ryuki and the mobile game Among Us, they wake up in a deserted island in the middle of nowhere, then suddenly a masked person appears, challenges them for a really horrible game, although they need to survive, as the only one who survived gets what they desire.
 * 2) The Masked Man, is a terrible game-runner as he set-ups really generic childish games that in reality, like the pot-game, chair-game and etc, and let me ask this why childish games, i mean their could have been any other way to give challenge them like a more sinister way, like a timed maze or a quicksand obstacle, but no party games, is he really that big of an idiot, and what's worse is the only person he could rely on killing the loser is Another Ryuki, then what is the murderer's purpose.
 * 3) The Plot-twists are awful, and are unsatisfying in general and doesn't make any sense, such as;
 * 4) * The Spin-off's Yuusuke being the Murderer, which is just so out of sync since the Original Yuusuke Onodera, is a selfless kind-hearted person and would even have the backbone not the be tricked by a random game for what he desires, but apparently this Yuusuke is just a spoiled power hungry murderer who only cares about his desires.
 * 5) * The Spin-off's Sougo is apparently a robot, and it was never explained where did he come from, is it impossible for him to appear in Kamen RIder Kikai's timeline since it was only the original sougo's dream timeline, and it was set in the year 2121, it was impossible for a time traveling wormhole to suddenly appear in that timeline, was he built by the Masked man, and apparently he likes basketball which just doesn't make any sense at all, since sougo never liked basketball and wasn't that skilled in any sport.
 * 6) * Misa Kuon is actually a deceased high-schooler who was killed months or years ago, it was never explained how she could be seen for a couple of rounds, or she was flung in to the deserted island or she could interact with others, seriously it's just flabbergasting.
 * 7) * And finally Heure/Uhr is actually a space ninja alien, from the Metal Hero franchise and he just suddenly bids farewell without explaining his connection towards the original Heure or how he was able to participate in the game.
 * 8) The Scene where the Masked Man identity was revealed, which was not other than Narutaki, was just really uninteresting, and it could be foreshadowed in the first two episodes that he is the one who made the death game, and once Tsukasa joined, he was probably the one who asked "Yuusuke" to exterminate him as fast as possible, only for him to request Tsukasa to exterminate Ohma Zi-O, which is just really confusing is he finally willing to aid Tsukasa or is it for him to get exterminated by Ohma Zi-O's hands.
 * 9) The Prize is just overall stupid, they would be sucked in a dimension where Ohma Zi-O is currently residing, only to be exterminated by Ohma Zi-O, really clever there huh.
 * 10) The Fight Scene was really underwhelming, and guess what the other three decade rider appear when Tsukasa never really needed them, and what's even worse is that it only existed so that Robot Sougo would only give Tsukasa the Saber Ridewatch, only for Tsukasa to deliver it again to the real sougo, and the ending was nothing but a big cliffhanger and a cheap gimmick to watch the other Spin-off.

Redeeming Qualities

 * 1) The Ending theme is at least nice to listen to.
 * 2) Tsukasa and Misa were the only likeable characters in this spin-off, and it was nice for Tsukasa to find out that the Yuusuke he encountered where Impostors which he clearly knew since Yuusuke is his close friend so he would clearly know that it's not really him, and it was nice for Misa to ally with Sougo and her sacrifice despite being underwhelming and noticeable, it was still somewhat sad to see her go, and her final scene where she said to Robot Sougo if she gets reincarnated, to meet a person like him, which is kinda cute and heartwarming.