Jeleva, Nephalia's Scourge
Commander 2013 Edition — Mythic
Legendary Creature — Vampire Wizard
When Jeleva, Nephalia's Scourge enters the battlefield, each player exiles the top X cards of his or her library, where X is the amount of mana spent to cast Jeleva.
Whenever Jeleva attacks, you may cast an instant or sorcery card exiled with it without paying its mana cost.