Riddle of Lightning
Journey into Nyx — uncommon
Instant
Riddle of Lightning rulings:
2021-03-19: If the chosen target is an illegal target by the time Riddle of Lightning tries to resolve, the spell doesn't resolve. You don't scry 3 or reveal any card.
2021-03-19: If a card in a player's library has in its mana cost, X is considered to be 0.