Tashni, Tevi Guru of Omens

At the beginning of your upkeep, look at the top three cards of your library. Exile one of them face down with an omen counter on it. Put the rest on the bottom of your library in any order.
You may cast spells with omen counters on them from exile. They cost {1} less to cast and can't be countered.
"Do not forsake these signs as mere conjecture. Should you continue on this path, you will die."