The sale will occur on the Immutable X marketplace. Each hero is fully playable in the game (once the game launches) and comes with their own exclusive perks and utilities. This includes access to exclusive leaderboards with their own sets of prizes, unique cosmetic items, and other collectibles, as well as potential access to real-life events and merchandise.
Guild of Guardians is described as a cooperative, fantasy, action, dungeon crawler game, currently in development on the Ethereum blockchain.