[Kurona]

No no, a lot of those examples very much count.

As the overlords were once the same entity and are just two sides of the same coin, the Lords and the Agito very much have the same basis.

The Rouse Cards being the monsters is as literal as you can get, but even beyond that the belts are directly based on Joker’s belt.

We don’t know much about Den-O’s belt but, yeah, it is quite literally kaijin in a rider suit vs kaijin.

Heisei 2 is littered with examples. Dopants, Greeed, Zodiarts, Roidmudes and Ganma all use or are made of the Riders’ gimmick items; the Wizard riders all have phantoms inside of them; Lockseeds originate from Hellheim; everything in Build is rooted in nebula gas and Evol’s machinations. Ex-Aid is a bit iffier but Emu is able to henshin at all due to having game virus, and the momsters all originate from Gashats. This is also the season where evil Riders really started to take over as the main villains, so make of that what you will. As for Zi-O, the Another Riders are made from corrupted Ridewatches and arguably the main villain is Sougo’s future self.

The Progrise Keys may have been made to counter the Ark but Ark and Zea are two sides of the same coin and keys get used by both MBJR and Thouser.