How long do you had to w8 for Lord Rderic?
I just dont get this card.. :(
Well honestly there is no way to tell.
Its just randomly.
Try to save a couple hundret coins (500+) and spend it in a short time.
A few days ago i've got seelenreßer twice that way. Still missing Rodric and other stuff, but honestly its just random, no chance to "farm" it or whatever...