Kamen Rider Ryuki: S1 E16 - Card Of Destiny Kamen Rider Ryuki

In pursuit of Ryuki, Knight and Raia rush into the Mirror World. They find Ryuki returned to his blank form now that Gai has stolen his contract card. Unless he retrieves the card he won’t be able to transform into Ryuki, and if the card is destroyed Shinji will be attacked by Dragreder.