The young man loses all his memory doesn't known his parents. After 10 years later, he worked the photographer living his adoptive grandfather and sister. But there is a world in danger. Tsukasa Kayoda chose our Hero as new Decade to traveled another dimension to save them. He is a Saviour or Destroyer?

2 Years ago NEO Dai-Shocker attempted to conquer the multiverse using the stone known as the Nexus. However, the heroes known as Kamen Rider fought to foil their plans and won. In the aftermath of the battle the worlds have fused into one, Shocker is still operating, and no Kamen Rider has been seen since. Now it is up to a new Kamen Rider to rise up and foil Shocker's plans once and for all.

This story got deleted not sure how but I managed to find a copy finally

[Reversed Isekai Kamen Rider Geats x Multi-Fandom Animeverse Crossover Remake!] Years after Ace Ukiyo become God of Genesis and the world is peaceful again. In real world, Acer is a fan of Kamen Rider Geats and Anime. He is a cunning fox that manipulate his enemy like Ace. He is have a rich mansion with his butler and his maid. Suddenly the Anime world start to collab with Real World but Ace use his power to merged many worlds together into one. Now people shocking to find Anime characters appeared in their world and Anime characters are shocked as they are fictional. One man start an new Desire Grand Prix to recruit Anime characters for their wish. Acer was chosen to become the next Kamen Rider Geats of Neo Desire Grand Prix to enter Multiverse Grand Prix. Now, this is his high light! Ready? Fight!

(Y/N)/Carnage: "Let there be...CARNAGE!!!!!!!!!!!!!!!!!!!!!" (Y/N) (L/N) was boyfriend of Rose Winters because the two of them are in the illusion of Miranda's nightmare until (Y/N) was saw his girlfriend have a trouble until he was release something sinister awaken inside at him and he change...into something worst for what they saw a nightmare...yes...a real nightmare of monster or devil for himself. Then (Y/N) had the symbiote inside at him and allow him to transform and become Carnage...because he called himself is The Devil King and yes...he become demon king and start to destroy enemies who were stood on his way and walk through the multiverse by himself with this power. There is only madness, chaos, death, and...Carnage!!!!!!!!!!!!!!

(Y/N): "Henshin." (Y/N) (L/N) AKA Ohma Zi-O/The Demon King who was the most powerful Dark Kamen Rider but he isn't a evil and he is kind of sort anti-hero and he found this belt that makes him become a user of Ohma Zi-O. The young man who lost everything that he care about his family also his lovely wife and two children that he care about and he want to see them again and he has been suffering like a lot with PTSD and traumas with nightmares about their death. Then the demon king who need to going to different universe and dimension where he is going and once he just got there and make him got in the different universe that he is in the Tokyo city and make him find something else surprise him that there was some monsters and magical girls who are strong. He can sense this world is being destroyed everything and what else is he gonna do? He gonna stood there and watching it but no...he must do with everything he can to make the world better.

(A/N: Yes, Blue Beetle in this story.) (Y/N) (L/N) Lorenzo is an African American who was enjoying his own life but he was become happy person for what he really care about and until there was a gift comes from someone who give this present box to him. Then (Y/N) open the box out and find there was an ancient of Scarab that (Y/N) never knew and what he was encounter it but he opened it up and it is attach to him when he was got inject by the Scarab and make (Y/N) change into something else for what he become...a hero...a superhero that he just become Blue Beetle. As for 5 years later that (Y/N) is a hero for the New York city to protecting the innocent people from danger but until out of nowhere there was a portal appear where he was on the roof and it is sucking him through the portal and take him to the timeline of future. After (Y/N) was being teleported into different universe that he is in the apocalypse with robots, drones, and machines but will he survive? Or will he meet with the other people like good or bad drones.

Reborn in the world of High School DxD, Roy is ready to conquer all with his Copy system. But he soon discovers that his greatest challenge isn't the devils or fallen angels, but the powerful and gorgeous girls inexplicably drawn to him. And with his ability that allows him to replicate the ability of those he touches, he will master everything.... [Do you wish to replicate this ability?] Roy: Yup, why not?

Taking the mantle of Kamen Rider Zi-O, Hikaro Cabral must gather together heroes from different worlds and dimensions in an effort to stop the Fallen from reviving in 100,000 days. But is it enough? When the Alliance comes across a strange artifact from the past, they find out that if they are to truly defeat their enemies once and for all and save the Multi-Verse too. However, they will need all the help they can get. But not from their Universe, the entire Multi-Verse itself!

Y/N L/N, childhood friend of Issei Hyoudou and Irina Shidou, was just an ordinary kid, up until he and his family moved to Kyoto and that changed his life forever. He found out about the his true heritage and that's he's the descendant of the Greatest and Kindest Demon King himself, Sougo Tokiwa or mostly known as Zi-O. Now, Y/N is a teenager and going back to Kuoh with his family, but what happens when he gets the attention of a certain red haired girl? Will his life continue as it is or will it become more interesting? Will he continue to live his life as it is or will he rise up and become the Demon King of Time and Space? Read and Find out... I don't own Kamen Rider Zi-O and Highschool DxD, they belong to their respective owners.