List of Kamen Riders that should be Mortal Kombat X DLC

Amazon
Stronger
Shadow Moon
Agito
Gills
Ren
Odin
Zolda
Ouja
Gai
Femme
Camo
Kaixa
Orphenoch variations of Faiz belts
Joker
Hibiki Riders especially Todoroki
Wing Knight played by Johnny Cage himself
Saga
Decade's Dark Riders from the Diend universe
The Akuma himself Decade
Baron
Micchy
Takatora/Zangetsu
Cid
Marika
Kurokage
Kurokage Warrior
Proto-Drive
Kamen Rider Mach, combined with special Kamen Rider Mach House, (Japanese film fans will get it.)

Bonuses:
Dark Heart played by Raiden's voice actor
Black Beet