Can you use (advanced rules) a patron card in an active slot? If so, it goes to the used cards but according to the rules you can put it right back in the slot? Then you can keep using activated patrons over and over again?
Or can you only use patrons that have not been activated yet or that have been replaced? (Patrons on the left side of your player board).
The rules says you use from the left side. Also there is a note for the patrons in the advanced rules which talks about how you can reuse a patron card after you bought a new one.