You need to exchange them once for one card to use them forever.
If you have no cards in hand when Fugitive Codebreaker's last ability resolves, you won't discard any cards, but you'll still draw three cards
Then each player draws a card
There are obvious flaws such as scratches, bends, and tears, usually caused by playing with the cards or not storing them properly
We're basically BigThreats.dec so we're packing lots of protection to help make sure nobody is messing with our smashing goals: Tamiyo's Safekeeping, Tyvar's Stand, and Gaea's Blessing all stop most forms of removal on Ghalta or similar beaters, and we've got haste enablers Surrak, the Hunt Caller, Surrak and Goreclaw, and Swiftfoot Boots to ensure we get the beats in asap