The Oneiromancer
Identity — Traitor (U)
Unveil {X}{X} (Start the game with this identity face down in the command zone. Turn it face up any time for its unveil cost.)
When The Oneiromancer is unveiled, each player exiles the top X cards of their library face down.
You may look at and cast cards exiled with The Oneiromancer without paying their mana costs. You can’t cast more than one spell this way each turn.