2023-09-01 : If the permanent that's exiled was the back face of a double-faced card, you will not be able to exile any additional cards, because those cards have only their front-face characteristics (including name) in the graveyard, hand, and library.

2023-09-01 : The cost-reduction ability of The End doesn't change its mana cost or mana value, only the total cost you pay. Specifically, the mana value of The End is always 4.