I say be descriptive with our characters. Be as detailed as possible when making your character's suit and personality.
World wise, I had an idea about a mirror world where you would enter a reflective surface and end up in another realm with an elemental theme like a snowy forest for ice users and a volcanic wasteland for fire users. The elements would be fire, water, earth, wind, ice, lightning, wood/nature, sound, light, and darkness.
Each rider would be bonded to a spirit animal like in Ryuuki, and the animals could also be split up in different species like African Elephant and Indian Elephant. These animals can take the form of a vehicle for real or mirrorworld transportation, and a real world animal form. For spirit animals that don't have a real world counterpart like dragons and unicorns they turn into a creature it would closely resemble. Their normal form (which would be larger and a unnatural form for the animal) would be only used when thy have to use their full power.
Each rider would also have a power unique to them like fire breath or hypnosis. These powers can be used in or out of the suit. These powers can be copied by the victor of a Rider vs. Rider battle. It can be more than 1v1 matches. Losers of these fights DO NOT DIE unless a life or death challenge is made. When you lose the match your body is destroyed momenterally and the flames surround the winner. The flames enter the victor's suit and they glow, proving the power has been copied. The winner then thrust out their hands forwards out of instinct and the glow flies out, reassembling the loser out of their suit, knocking them out. At most 3 powers can be used at the same time.
The riders have 4 forms: normal(no suit but the belt appears like in Kuuga), rider form, Were form(the spirit enters the rider suit like a gas and turns the rider into a half man - half animal with different clothing), and Master form(the spirit bonds with the rider, the rider's body changes into light, and the rider's clothing changes into something that covers all the skin). There are other possible forms that are temporary, curses, come from items or other rider powers, or could be helpful or harmful.
That's the idea I have for a Rider RPG. Use whatever you like from it.
