Empathic Weapon: The Kamen Riders are a deck with their own spirits.

This also stems to his monsters, the disco-themed Boogie Knights. From the way he dresses to his speech and mannerisms, he lives, talks, breathes everything disco.

Disco Dan: Koji is the living embodiment of this.

Disappeared Dad: Kuogasa's father, Kyoshiro.

Subverted as his friends talk him out of it, as well as the spirit of his dead mother.

Despair Event Horizon: Kurogasa goes through this once he learns from Orpheus that his mother died giving birth to him and is responsible for most of Tarakudo's actions.

Combining Mecha: This is done during the Rider War, by SYRUS no less!.

Cool Bike: Kurogasa rides one on the way to the Duel Academy Exams.

Chekhov's Gun: The gauntlet which somehow contains the spirit of Kurogasa's dead mother Yukina.

Childhood Friends: Kurogasa, Koji, and Rika have been friends for quite some time.

Catchphrase: I am the soul of all Kamen Riders, Kamen Rider Duelist!.

Card Games: Because it is SERIOUS BUSINESS!.

The Cameo: The Paradox Brothers, Arkana, WWE, Yugi and Joey, Pegasus, Kaiba, the list goes on.

Bond Creature: Kurogasa and his Kamen Riders, Rika and the Foodons, Kyoshiro and the Showa Riders.

Turns out Orpheus is possessing Tarakudo Shinryuu, Kurogasa's uncle on his mother's side.

Brainwashed and Crazy: The Shadow Riders, but could be a form of possession also.

Black Magician Girl: Guess who makes an appearance, and becomes part of Kurogasa's deck?.

In Season 2, we have, but who else, the Society of Light's Sartorius.

Kamen rider ooo crossover fanfiction