The Witch's Vanity is a key card in that deck
Assuming it survives, you put it into your hand at the end of combat
With Marneus on the field, every opponents draw step generates treasures, which are immediately converted into additional card draw
Wizards has pulled out all the stops to publicize the set, knowing that the tie-in to a massive gaming franchise will draw the eyes of thousands of new players to Magic when the set does come out
The same is true of cards found digitally in Magic: The Gathering (MTG) Arena, though for some reason its not immediately obvious or intuitive as to how players do this
I also threw in the more powerful venture cards just to maximize that AFR feel (and our odds of a 2-turn dungeon clear) with the exception of Acererak, who isnt quite as cool when we want to smash out repeated loops of Tomb of Annihilation compared to just one