Here's a look on Kamen Rider Joker. Based on the design, its like JokerJoker from the Kamen Rider Decade X W: Movie Wars 2010 movie. Obviously behind the mask is Shotaro! But the question is, how did he get Oyasan's Lost Driver?
Kamen Rider Joker Rider Punching a Masquerade Dopant!
Here is a scene where Kamen Rider Joker is fighting against the Metal Dopant.