Kamen Rider Blade X BanG Dream X D4DJ the 4 aces

after the Battle fight from 1000 years ago God created the buckles for 4 riders with four undead that was sealed. Takumi who is a young man who works at Board of the archeology and research department known as board when an Undead escaped the place was abandoned. he was adapted by Rinku's parents when his mom and dad died in a plane crash he still knows his members in Board.