Big Bad: Gara, one of the four Alchemists that created the Greeed for the First OOO.
Demonic Possession: Gara long ago lost his body after the King betrayed him and turned him into Cell medals along with his fellow alchemists, so he has to possess a human after being awoken in modern day.
Dug Too Deep: The Kougami Foundation's archaeological dig unearths Gara's tomb in search of secrets he may have buried with him, accidentally unleashing the mad alchemist on the modern world.
Early-Bird Cameo: Not only does OOO's successor, Kamen Rider Fourze, make his first appearance in this movie, but so does one of the supporting cast members of his series. In this case, Yuki Jojima.
Evil Cannot Comprehend Good: Gara has no comprehension of positive desire, and is perplexed by Kougami's assertion desire is a creative force, not a destructive one. This ultimately ruins Gara's plan, as Eiji's overflowing selfless desire to save the people around him overloads his machine when Gara was expecting him to be a self centered monster like the original OOO and himself.
Evil Versus Oblivion: The reason the Greeed oppose Gara and help OOO defeat him. That and he stole their Core Medals.
Fastball Special: Eiji gets fascinated when Fourze demonstrates his powers, until Fourze decides to use the Magic Hand Switch to throw OOO at Gara.
It Was a Gift: OOO receives the medals for his BuraKaWani combo from Tokugawa Yoshimune.
Mook Maker: Gara is capable of making entire armies by himself.
Omnicidal Maniac: Gara wants to destroy the world so he can remake it In Their Own Image. Mezool compares him and Maki, but Maki quickly shoots down the assumption, as while he also wants to destroy the world, Gara wants to make a new one In Their Own Image afterwards while Maki wants the end to be the end.
One-Winged Angel: Gara transforms into a a monster form after his initial plans are ruined. He transforms again after being defeated by OOO and Fourze, turning into a gigantic chimeric dragon-like monstrosity.
Sealed Evil in a Can: Gara was sealed in Germany until Kougami accidentally unearthed his tomb and set him free.
You Have Outlived Your Usefulness: Gara and his fellow Alchemists were subjected to this by the First OOO after completing the Greeed, turning them to Cell Medals. In Gara's case, he eventually revived.