Whenever you cast a creature spell with infect, target player gets a poison counter
Of course, four mana is a much steeper investment than Brainstorms single-mana cost, so Jace really only pays off in the long run
Magic: The Gathering is going cosmic in the Edge of Eternities set, as Spacecraft cards are coming to the game, which are incredibly powerful artifacts that require a lot of power to get going
Representing a scaling down of power levels common in many cards from The Dark, it can still devastate a deck that relies on creatures like Llanowar Elves or Birds Of Paradise to generate extra mana, destroying them en masse if they don't attack
Plus, it also helps players to visualise Duskmourn as a haunted mansion, adding to that sense of spooky exploration