No longer a mystery.
Card of Spirit
Normal Spell
You can only activate 1 “Card of Spirit” per turn. (1) Each player chooses 1 card from their Deck, then each player chooses 4 random cards from their opponent’s Deck, and if they do, each player shuffles the 5 cards chosen from their Deck, randomly picks 1 to reveal and add to their hand, and shuffles into their Deck the rest of the cards chosen from their Deck.