Kamen Rider: The Ryuki Chronicles

Years pass by ever since the rider battle came to a closing, but now scientists attempted to explore the other world with a great cost of lives being taken by the black dragon rider Ryuga. Since then, there has been an advancement of the city as the son of the deceased head scientist, Mizaru, now seeks revenge against Ryuga. The only way to unravel the mystery is for him to ride the Advent as Kamen Rider Knight and compete in the newly awakened rider battle.