Slaves of Bolas

+1: Draft a card from Slaves of Bolas's first spellbook. Exile it. You may cast it for free when Slaves of Bolas leaves the battlefield.
-2: Draft a card from Slaves of Bolas's second spellbook. Exile it. You may cast it for free when Slaves of Bolas leaves the battlefield.
-9: Draft 3 cards from both of Slaves of Bolas's spellbooks. You may cast them for free. Destroy Slaves of Bolas.