give the narrator the ability to edit characters cards.
In one of my games a character picked a goal up by accident and there was no way for him to give it back. Requesting revisions didn't help here. So either players should be able to trade cards (or give them without something in return) with the narrator's permission, or the narrator should be able to take cards from players.
Also it could be useful to edit cards later on to add images or correct typos.

In Gamma the narrator can edit cards at any time, including cards that players have already picked up. Narrators always retain a copy of cards they play or give away, and editing that copy applies the changes everywhere.