crucial information

Choose an opponent, this player show is
hand and the card on top of is library
then replace it at their place. Name a card,
the target opponent can't use it until the
begin of your next round.
———{line}{line}{line}{line}{line}{line}{line}{line}{line}{line}{line}{line}{line}{line}
So my little one, what are they planning ?
. Admiral Strategist Obero