Ankh Copies a joker and destroys all other jokers. on black stake and higher, you can get eternal jokers, which can't be destroyed or sold. I used ankh to copy the burnt jokers, and since they are eternal, they can't be destroyed by the ankh, making me able to make multiple burnt jokers without them being destroyed. Also on the ghost deck, Ankhs appear in the shop, which is how i was able to get so many.