Once Upon a Time, there was a god named Gentaro Kisaragi. He came to the Pantheon as a way to “befriend every god” there, and he and the Kamen Rider Club spent their days on the moon, hanging out with friends, and living life like there was no worries at all.
But then, that came. That world where everything changed from one mistake. When Gentaro saw that world, he was crushed. Nothing could stop his depression, and when the Kamen Rider Club saw the changes, they too felt despair. But while they were able to hang on, Gentaro couldn’t. He was tormented by visions of an alternate Pantheon, where he killed his friends. No one could help him, and he soon caved into that anguish.
He was reborn as Alternate!Gentaro.
He chose four gods to aid him for a goal, what said goal was no one knew. In his crystalline castle, he was ready to unleash part one of a deadly attack to crush the Pantheon. There were many gods who were involved in the creation of the alternate god, but who the mastermind was…that was harder to pinpoint. The Gods of Justice were able to figure out a name for this entire situation.