Masked Rider Episode #1: "Escape From Edenoi, Part 1"

[PrimoPiccolo]

Dex, prince of Edenoi, is sent from his home world by his grandfather to Earth, in order to escape the clutches of his evil uncle, Count Dregon. His journey begins here.

[mbozzo]

I remember the first episode. One of the monsters from Kamen Rider ZO appeared in that episode. I still don't know why the writers didn't have Dex wearing the Kamen Rider ZO costume in this one. :o

[PrimoPiccolo]

I still don't know why the writers didn't have Dex wearing the Kamen Rider ZO costume in this one.
Undoubtedly, it's because they didn't actually have the suit on hand. Both Masked Rider and VR Troopers were created so long after the series they used as source material, they barely had any of the costumes to shoot new footage with.

The much better question would be why on Earth they needed to use ZO footage at all. It's not as though they exhausted every creature Black RX fought over the course of Masked Rider.