[Jkin62]

Who would it be?
Yes yes I know I just did this with Secondary Riders but now I'm all in the mood for this so eh.
Quick rundown, it's the apocalypse. It's a cross between the Legend War from Gokaiger and Crisis City from Sonic '06.

That's where you come in.
You can use the powers of any Rider that's not a Primary or Secondary Rider. Other than that I say go nuts. Movie exclusive Riders? Go ahead. Villainous Riders? Knock yourself out. One off Riders? I don't see why not. So long as they're not Primary or Secondary.

This one was kinda tough for me but I decided I'd go with Necrom. I picked him mostly because I like his two Eyecon Forms and if I run into a Ghost or Specter I can use their Eyecons as well. Plus I reeeaaaally dig his henshin.
Second choice would probably be Zangetsu Shin. Of all the Energy Riders we see I think Zangetsu Shin looks the coolest. Though using the blade part of the bow as a weapon might take some getting used to since I'd have to swing it with my left hand and I'm right-handed...
Third choice would be Kamen Rider Fifteen. Because Legend Rider Lockseeds.