Yohtenn, the Raven's Eye

When Yohtenn, the Raven's eye enters the battlefield, look at the top four cards of target opponent's library, then put them back in the
same order.
At the beginning of your upkeep, you may
choose a card name. The next time an opponent
casts a spell with the chosen name this turn,
Yohtenn, the Raven's Eye deals damage equal to
that card's converted mana cost to any target.