How do these decks work? I'm kind of new to the ACG but wondering about the add-ons. I figure it's a bunch of extra cards but do you just add them to your campaign box mixed with everything else? Or are they used separately for some purpose? If I want to play another campaign, do I have to remove the ones that come in this one? (I know you can tell by a symbol thing). A playable character is undesrtandable, but not quite the rest...

Do wanna play Hayato, but want to understand what I'm buying here.