[MrHerofan]

Well how about a mil tipple rider series except with four main riders?
So it's sorta confusing but could work. So there are two class of riders. One class is a low class where anyone can use it. So in the lower class these riders can be anyone. They fight to the death weekly and when one person wins they get points and after enough points they can go to the next class where they fight with others of their class to the death again and remain champions until they die. The powers of the lower class riders are given to the victor and he/she gives it to some other person. The upper classes drivers are given or found by another. The motif could be knights for the upper class, and foot solders of the lower class. They can use discs the lower class uses to henshin while the upper class has unique drivers that use the discs.