[zenstrive]

I remember Ryuki has an ending in which Shinji, Ren, and Yui in a room, facing a window in a room in high elevation while watching a horde of flying monster. Is that Episode Final?

If that one is reset by Shiro, then Ryuki's characters really has no powers whatsoever in the end, explaining the absence of Ryuki. But how does Dark Shinji's Ryuga power exists to have his power corrupted into Another Ryuga? And what about the rule of Another Rider can only be destroyed by its real form's power?

How does Ryuki able to crossover into those taisen movies anyway?