Sota Mizushino was watching the anime "Elemental Symphony of Vogelchevalier" in his room when suddenly, Selesia Upitiria, a character from the anime, and a mysterious girl dressed in a military uniform appear in his room. Sota gets caught in the middle of their battle and follows them to Yoyogi Park, where Meteora Österreich, a character from the game "AVALKEN of Reminisce", suddenly appears.

Sota tries to fulfill Selesia's wish to meet the Creator of her story, and contacts Takashi Matsubara, the author of "Elemental Symphony of Vogelchevalier". Selesia waits for Matsubara at Ikebukuro when Mamika Kirameki, the main character from "Magicalslayer Mamika", suddenly appears. Mamika, angry at the Creators who created sad stories, and Selesia, who opposes her, start battling...

Selesia gets rescued by Yuuya Mirokuji, a character from the manga "Exclusive Underground."

Meteora hypothesizes that characters possessing special powers interfering in the real world could cause the world to be destroyed. Meteora realizes that her Creator loved everyone who plays the video game she stars in, and vows to stop The Great Destruction to protect the people her Creator loved. Meanwhile, Alicetaria February from "Alicetaria of the Scarlet" joins the Military Uniform Princess.

Matsubara visits screenwriter Masaaki Nakanogane's house where he finds Rui Kanoya from "Monomagia: The Infinite Over Machine."

Meteora senses that a new Creation has appeared in the world, but arrives at the scene only to find the aftermath of a massacre. Meawhile, Mamika and Alicetaria run into Magane Chikujouin from "Yasou Kiroku" while searching for Creations to join their cause. Mamika asks her to join them, but Alicetaria notices the scent of blood. Selesia arrives in search of Magane, and a fierce battle ensues.

Mamika intervenes in a fight between Mirokuji and Blitz in order to stop people who can only reach an understanding through fighting. For the sake of the people in her world, and for the sake of fulfilling her role as "Magical Slayer Mamika," Mamika asks Souta about the truth behind the world. Meanwhile, Nakanogane discovers the Military Uniform Princess's true identity on a video posting website.

The true identity of the Military Uniform Princess is Altair, a secondary creation of the character Shirotsumekusa from a social game called "Eternal Wars Megalosphere."

Mamika is fatally injured in a battle with Altair, entrusts her dying wish to Magane, and dies in Alicetaria's arms. Magane twists Mamika's dying wish, making Alicetaria's rage turn on Meteora. Magane tells Souta about Mamika's death, and makes him believe he's responsible for her death. Mirokuji and Meteora come to save Souta and start battling Magane, when suddenly Alicetaria arrives...

Yatouji succeeds in luring out Alicetaria, but is interrupted by Magane and falls prey to her Infinite Deception of Words. Meanwhile, Selesia rushes to help Meteora and faces off against Alicetaria. However, Altair interferes in the battle and makes Selesia's weapon vanish, and Selesia gets stabbed by Alicetaria. With Selesia on the brink of life and death, Matsubara tries revising the story again.

With Selesia and Meteora suffering critical wounds, the team is left in poor shape after their battle with Altair.

Souta deals with his feelings of guilt and regret for not being able to save Setsuna Shimazaki and vows to stop Altair. Altair is different from ordinary Creations: Altair's powers grow with each new spin-off story made about her, but Meteora's powers are limited to her character description. Meteora comes up with a plan to revise their character descriptions and get the support of the viewers.

Meteora recaps the events of the story up until now, providing her own perspective and embellishments while also providing more backstory of each for the creations and their respective series.

Hikayu Hoshikawa, a character from the dating sim video game Starry Sky Milky Way, appears in front of the group. Hikayu doesn't possess any abilities for battle but is still required to participate in the Elimination Chamber Festival since she's a Creation. Oonishi, Hikayu's creator, comes up with an idea to help her. Meanwhile, a new Creation joins Altair's side...

The Creators, exhausted after the tight deadlines, and the Creations, who have been executing the plan, get a moment to relax before the real battle starts. The team rallies their spirits for the upcoming battle, each member recalling their own reasons for fighting: To save the world, to return home, to face the past; Selesia and the others enter the Bird Cage, where they lie in wait for Altair.

The battle over the fate of the real world and the fate of the story worlds finally begins! Selesia is able to get back into Vogelchevalier again after winning the acceptance of the audience, and faces off against Altair. However, her new powers don't work against Altair, and she struggles in the battle. Meanwhile, Blitz goes to pay someone a visit to tie up some loose ends.

Magane pays Souta a visit while he watches Selesia's battle and tells him that he is just like her because they both use others to satisfy their own desires, laying the groundwork for her plans to make things "more interesting." Meanwhile, Alicetaria, Blitz, and Shou turn against Altair in the Bird Cage, and join Selesia's side instead. However, Altair still has one final trick up her sleeve!

Selesia and the others encounter the final Creation, who turns out to be Charon, the hero from Elemental Symphony of Vogelchevalier, the same story Selesia comes from! While Selesia is overjoyed at the reunion, Charon is sick of the endless fighting in his world, and joins Altair, who is trying to destroy the world. Selesia refuses to fight against Charon, and makes up her mind in a big decision.

After losing Alicetaria and Selesia, Meteora and the others try to trap Altair within the Bird Cage, but the audience sympathizes with Altair and transforms the Bird Cage into a stage for amplifying Altair's powers! Meteora tries to turn the tables on her by bringing out their secret weapon: Sirius, a Creation with the same appearance and the same powers as Altair!

Altair incorporates Sirius into herself and overpowers the other Creations, bringing the world to the brink of The Great Destruction! Meteora and the others try to save the world by making Setsuna Shimazaki, Altair's Creator and their last hope, appear in the world. Altair and Setsuna encounter each others as Creations in the same world, and begin to reveal their true feelings to each other.

The Elimination Chamber Festival ends successfully, and everything draws to a close. As the Creations prepare to go back to their own worlds, they spend their last few moments enjoying the real world. On the day of parting, the Creations return to where they each belong, each carrying their own thoughts in their hearts.