thanks LoweGear
hey my assumption about the booker is correct Xd
The Ride Booker's power source and storage space is a 4-dimensional pocket made out of a Klein bottle. Thus it can store an infinite number of cards. The Ride Booker reacts to the user's will and selects the desired cards automatically. To make it simpler, it's literally Doraemon's pocket when it comes to cards.
I guess the same principle applies to Ryuki also--damn it I want to draw a survive card but it keeps getting me something else