If an exiled card has {X} in its mana cost, X is 0 for the purpose of determining its mana value.
2025-06-06 • wotc
You follow all timing rules for cards played this way. For example, if the exiled card is a land card, you may play it only during your main phase while the stack is empty and only if you have an available land play remaining.
2025-06-06 • wotc