Yes, that is what I was referring to. I feel like you should have unlocked that rule before the end of game 2, but it doesn't change much. From now on, during setup you can pick any persona you have unlocked to give you a special ability for that game. Personas that you unlock during the game go into your charter chest to be used in future games.
Charles, I don't think he's confused about how they work, but about when he can start using them since he has not unlocked the new rules for setup that account for choosing personas.
Peter, I'm honestly not sure. But for what it's worth, our group did allow for personas in the second game.