Arthur makes it possible to return chosen characters to a player's hand for extra lore, working nicely with an Amber/Amethyst deck emphasizing cheap character cards
The idea of the service is pretty simple: if you have a bunch of Magic cards to sell, then rather than spending the time and effort of sorting, buylisting, and shipping your cards to a bunch of different vendors, you can just send your cards to Card Conduit, and it'll do all of the sorting, buylisting (to the best vendors), and shipping (apart from the initial shipment to get your cards to Card Conduit) for you
The only change Id make would be to give the Knights one or two cards with reach so they can at least have a chance of blocking those flying dragons
Its owner shuffles it into their library, then investigates
First deck out of the gate is a Relentless Rats deck with Marrow Gnawer from the Kamigawa block