I think a fun thing to do would have a second series of mark cards, that are usable. and when you use them, it changed your mark free, but then that card disappears. They would be uncommon, maybe even rare. That way you can change your mark easily if you have a second series Mark Card, but you can only change into a mark of the mark card you have, so you might not have the one you need. Maybe even a Quantum Mark Card that will change your mark into a random one.