Mortov, Cursed by Knowledge

Whenever Mortov enters the battlefield or
attacks, each player exiles the top card of their
library face-down.
When Mortov dies, you may exile it. When you
do, target opponent looks at the cards exiled with
Mortov and separates them into a face-down pile
and a face-up pile. Choose a pile, then reveal each
card exiled with Mortov. You may cast any
number of cards in the chosen pile without
paying their mana costs.