2023-02-04
If the target creature is an illegal target by the time the spell tries to resolve (most likely because it has left the battlefield in response), the spell will not resolve. No card will be exiled.
2023-02-04
You pay all costs and follow all normal timing rules for a card 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.