Kerian's Shadow

When Kerian’s Shadow enters the battlefield and at the beginning of each of your upkeeps, choose a player, that player is the target of Kerian’s Shadow until the beginning of your next upkeep.
You can see target player’s hand. Whenever this creature attacks, you can instead Foretold X, where X is the power of Kerian’s Shadow. Kerian’s Shadow is unblockable and can only attack target player.
{1}{b}: Return Kerian’s Shadow from your graveyard to your hand.