This wont actually go in all decks despite what it feels and seems like
Surfaces: Corners
If they dont pay, they cant attack you
A pitch-black, endless, and shifting labyrinth is hard to get through for the novels characters (and maybe for some a 700-page novel is just as hard), and by dividing up the battlefield in these ways, especially if both are on board at once, we can make traversing combat difficult for our opponents attacking creatures (in the case of River) or blockers (when it comes to Space Jace, who also threatens a 1/3 board wipe at any time)
Then, while completely unannounced and hidden by the game (a repeated issue), there are also a bunch of new Solo Step-Up Battle challenges to complete, offering five more hourglasses for each stage
Many excellent articles have been written about the brewing process, but this will not be one of them because I am a tuner and this is an article about the tuning process