The main two features that come to mind are the ability to edit a card once it has been published and the ability to make a published card private
Or take a look at all the games Promo Cards and how you can get hold of them to either fill out that Pokedex or destroy others in battle.
The Party Time Commander Legends: Battle for Baldurs Gate Commander Deck set includes 1 ready-to-play White-Black deck of 100 Magic cards (3 traditional foil, 97 nonfoil), a 2-card Collector Booster Sample Pack, 1 foil-etched Display Commander (a thick cardstock copy of the commander card with foil etched into the cards border and art), 10 double-sided tokens, 1 deck box (can hold 100 sleeved cards), 1 life tracker, and 1 reference card.
The Scrap Trawlers are here to show you how to upgrade the Food and Fellowship precon from Lord of the Rings: Tales of Middle-earth
Plus I do so love my zombie assassins
Low stakes, low budget, maximum fun per dollar spent