Four Riders: Wizard, Gaim, Apprentice, Dreigon! All of them have different adventures, but each must now take part in something which will all bring them together, but at what cost? (Has a lot of errors in grammar, plot, and spelling, particularly in Part 6, sorry)
Sometime in the future, the Spider Riders encounter a man calling himself: "Z". Afterwards, a series of events start, revealing the existence of something called Helheim. And the only thing with the power to go against it is the Sengoku Riders. Only problem is that they may destroy each other first. (Knowledge of both series needed to understand. Warning: Character Death)