They have identical stats and abilities to their standard-art counterparts
Its utility is dependent on what you get from the spell resolving, so the ceiling is high and the outcome open to creativity
the Eowyn-led Riders of Rohan, Food and Fellowship (with Frodo and Sam on the cover), Elven Council with Galadriel, and the Sauron-fronted Hosts of Mordor
Geralf, the Fleshwright creates a Zombie token when you cast any spell that's not your first spell that turn, Open the Graves creates a Zombie token when a nontoken creatures you control dies, and Cryptbreaker makes a Zombie token by discarding a card and tapping itself
Sure, you lose life in exchange, but being able to take a problematic enchantment the second it becomes a problem is a huge boost to black decks