I had been hoping for this eventuality, ever since Fool!
Flagbearer - This makes me imagine Flagbearer slogs, where Flagbearer is the best $4-cost card because of the advantage it takes away from your opponent. I'm sure it doesn't happen often, if at all, but I hope it happens sometimes at least a little. I like that Flag is friendly, so that if both players buy one, then they both get 6 cards.
Swashbuckler - Um that art. Although, I looked up the word, and it seems that "swashbuckler" is a heroic archetype in fiction, so I guess depicting a Hollywood pirate is just about right. Seems like it shines most in a good stuff deck, where you're more likely to have a discard pile, and you're more happy with gold-gaining. Oh, and if everyone collects Coffers, everyone gets gold, yay!
Is Swashbuckler the card that cares about shuffling?
Treasurer - So it's like a Moneylender, but you can either lend or borrow. The key, unlike the other artifacts, is unfriendly. You can reach a point where players swap the key and nobody gets the bonus.