Cids an excellent equipment bearer, and recurring cards gives the deck power
banish all monsters your opponent controls
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)
Collectors often use jumbo binders, oversized sleeves, and acrylic cases to protect these cards
The image on the back doesnt scrape off or chip from shuffling, which presents an incredible amount of friction and wear on the sleeves
You're unlikely to beat them, especially if they can re-buy Jace or are supplementing with some other form of Mill