The Grishoalbrand and Tin Fins decks, respectively
Dollmakers Shop // Porcelain Gallery Getting a free token each time you attack with Dollmaker's Shop is strong, kind of like a Wedding Announcement thing
Black and white also both excel at recursion, so you can rebuy cheap utility enchantments like Hopeless Nightmare to get multiple triggers in the late game
Then when you discard, you exile it instead, so that you cannot recur or flashback anything
Some D&D players really enjoy the idea of breaking the game, and Im sure that the above combo will show up in a number of Cubes around the world for this very reason
In game terms, Elsa has an Ink cost of 8, a Strength value of 4, 6 Willpower and 3 points of Lore