|This article is about a/an episode in Kamen Rider Decade.|
The Destroyer of Worlds (世界の破壊者 Sekai no Hakaisha) is the thirty-first and final episode of Kamen Rider Decade, the concluding part of the series' endgame, the World of the Rider War. The only Kamen Rider Series finale to end on a cliffhanger, Decade's story was concluded in Decade: Final Chapter, which formed part of the Movie War 2010 crossover feature with Kamen Rider W.
On October 4, 2009, TV Asahi began a re-broadcast of the series from beginning to end at 6:30 am timeslot. When episodes 30 and 31 were rebroadcast on May 2 and 9, 2010, respectively, they were recut with some scenes extended and others cut, labeled as "Special Edition" (特別編 Tokubetsuhen) versions, this episode being given a new conclusion.
As Blade, Kiva, and Hibiki's Worlds continue to merge, Super Apollo Geist has captured Natsumi, sending a challenge to Decade. But a new Kamen Rider Blade has appeared, Kazuma Kenzaki, and he says that those who ally with Decade will disappear because of it.
After fighting off the Riders, Super Apollo Geist takes Natsumi to be his new bride as he flees. Kazuma Kenzaki appears, saying that Tsukasa's existence is the real cause of the worlds blending before confronting him as Kamen Rider Blade in King Form in order to force him to leave the world at once with Asumu keeping Yusuke and Wataru from interfering as Decade is easily defeated. After returning to the Hikari Studio, Tsukasa is recuperating while learning that all of his photos are starting to vanish as a result of the worlds' fusion; Eijiro gives him hope with a photo of Natsumi and tells him not to give up. Following Kiva-la, Tsukasa is attacked by Wataru and Asumu, whom Kenzaki recruited so they can save their worlds, after he refuses to leave. Kuuga gets Tsukasa to run off so he can save Natsumi while he holds Kiva and Hibiki off, though briefly torn by his loyalties. Meanwhile, Super Apollo Geist resurrects the Beetle Fangire, Paradoxa Undead, Tiger Orphnoch, Taurus Ballista, Alligator Imagin, and the Phylloxera Worm. The next day, Tsukasa finds Super Apollo Geist's base as he meets Daiki who warns about the trap arranged for him. After promising the world to Daiki if he dies, Tsukasa arrives to stop Guy as he is about to consume Natsumi's life energy, fighting both Super Apollo Geist and the monsters with aid from Kuuga and Diend. With Kiva and Hibiki joining the fight, the Riders take out the monsters. After Yusuke gets injured protecting him, Decade uses Diend's Final Attack Ride card to kill Super Apollo Geist. With the battle over, Natsumi soon recognizes that she is in the exact place where her dream takes place as Kiva and Hibiki fade away with the Nine Worlds destroyed, with only Yusuke surviving. Tsukasa is suddenly transported to the dimension where he had spoken with Wataru Kurenai, who becomes Kamen Rider Kiva after he told Tsukasa that his true mission was to defeat the eight A.R. Heisei Riders, not befriend them. Soon, Tsukasa finds himself back in the World of the Rider War, confronted by seven of the nine other Heisei Kamen Riders, Kenzaki then stepping forward and becoming Blade King Form; Tsukasa transforms. Kiva-la then bites Yusuke to revive him, but by turning him into a black-eyed Kamen Rider Kuuga Ultimate Form. With Narutaki overseeing it, the Rider War commences as the nine Riders face Decade, lasers beginning to fire around them, and Diend suddenly runs up and fires the Diendriver at Decade at point blank range.
Identical until Tsukasa finds himself back in the World of the Rider War, confronted by seven of the other Heisei Kamen Riders. He transforms, when an Ultimate Kuuga with black eyes arrives (no longer identified as a revived Yusuke), Blade King Form also suddenly appearing in the crowd (Kenzaki's brief transformation scene was removed). With Narutaki overseeing it, the Rider War commences as a huge Rider army joins the brawl (reusing scenes from the dream in the beginning of the first episode). As in Natsumi's first dream, after the chaos Decade emerges victorious, with many Riders dead around him, while Natsumi wonders about the meaning of their journey and Decade's battle.
- Tsukasa Kadoya (門矢 士 Kadoya Tsukasa): Masahiro Inoue (井上 正大 Inoue Masahiro)
- Daiki Kaito (海東 大樹 Kaitō Daiki): Kimito Totani (戸谷 公人 Totani Kimito)
- Yusuke Onodera (小野寺 ユウスケ Onodera Yūsuke): Ryouta Murai (村井 良大 Murai Ryōta)
- Natsumi Hikari (光 夏海 Hikari Natsumi): Kanna Mori (森 カンナ Mori Kanna)
- Eijiro Hikari (光 栄次郎 Hikari Eijirō): Renji Ishibashi (石橋 蓮司 Ishibashi Renji)
- Narutaki (鳴滝): Tatsuhito Okuda (奥田 達士 Okuda Tatsuhito)
- Kiva-la (キバーラ Kibāra, Voice): Miyuki Sawashiro (沢城 みゆき Sawashiro Miyuki)
- Guy (ガイ Gai): Kazuhisa Kawahara (川原 和久 Kawahara Kazuhisa)
- Decadriver Voice, Diendriver Voice, K-Touch Voice (ディケイドライバー音声、ディエンドライバー音声、ケータッチ音声 Dikeidoraibā Onsei, Diendoraibā Onsei, Kētatchi Onsei): Mark Okita (マーク・大喜多 Māku Ōkita)
- Narration (ナレーション Narēshon): Eiichiro Suzuki (鈴木 英一郎 Suzuki Eiichirō)
- Wataru Kurenai (紅 渡 Kurenai Wataru): Koji Seto (瀬戸 康史 Seto Kōji)
- Wataru (ワタル Wataru): Arashi Fukasawa (深澤 嵐 Fukasawa Arashi)
- Asumu (アスム Asumu): Kazuki Koshimizu (小清水 一揮 Koshimizu Kazuki)
- Kazuma Kenzaki (剣崎 一真 Kenzaki Kazuma): Takayuki Tsubaki (椿 隆之 Tsubaki Takayuki)
- Formica Pedes (フォルミカ・ペデス Forumika Pedesu), Kamen Rider Ryuki (仮面ライダー龍騎 Kamen Raidā Ryūki), Kamen Rider G4 (仮面ライダーG4 Kamen Raidā Jī Fō, voice) : Katsumi Shiono (塩野 勝美 Shiono Katsumi)
- Kamen Rider Decade: Seiji Takaiwa (高岩 成二 Takaiwa Seiji)
- Kamen Rider Diend: Eitoku (永徳)
- Kamen Rider Kuuga: Norihito Itō (伊藤 教人 Itō Norihito)
- Apollo Geist, Past Riders: Jun Watanabe (渡辺 淳 Watanabe Jun)
- Card Used:
- Kamen Rider Decade:
- Kamen Ride: Decade
- Attack Ride: N/A
- Form Ride: N/A
- Final Form Ride: N/A
- Final Attack Ride: Diend
- Final Kamen Ride: Decade Complete
- K-Touch: N/A
- Decade, Complete Form
- Kamen Rider Diend
- Kamen Ride: Diend
- Attack Ride: N/A
- Final Form Ride: N/A
- Final Attack Ride: N/A
- Kamen Rider Decade:
- Though likely intentional, Decade Complete Form uses Diend's Kamen Ride Card instead of his Final Attack Ride Card to trigger their dual attack, though it's still announced as if it were a Final Attack Ride.
- As part of Super Hero Time, this episode aired alongside Samurai Sentai Shinkenger episode 27, Act 27: Switched Lives.
- Viewership: 6.8%
- In the cut aired on reruns, an unidentified Ultimate Kuuga, with black eyes, appears after Wataru told Tsukasa's true mission. When more Riders appear and the Rider War starts, Kuuga seemingly reverts to Mighty Form and boards the TryChaser 2000, although he's knocked out during the conflict.
- In the original version of the episode, the Ultimate Kuuga in the final battle was a brainwashed Yusuke Onodera, but all references to his identity are removed in the rerun version, which just makes him appear as another member of Wataru's group. TV Asahi site also lists this Kuuga as a separate character.
- The Rider War stopped in a cliffhanger. Continuity started during Movie War 2010.
- The sudden end of Rider War was used as a joke at Kamen Rider Decade: Final Stage, though the stageshow do not take place within the period of Rider War.
- As of this episode, Kamen Rider Kuuga is the only show from the Heisei series that doesn't feature any character returning in Decade.
- Decade's battle with Super Apollo Geist was seen in Kamen Rider Battride War.
- This is the first and only time Wataru Kurenai transforms into Kamen Rider Kiva outside of his series.
- This is the first time where Kazuma Kenzaki transforms into his King Form straight from his civilian form.
Blu-ray Box comes with all 31 episodes.