+2: Target opponent exiles cards from the top of their library until they exile a nonland card. Until end of turn, you may cast that card without paying its mana cost.
−4: Nicol Bolas, God-Pharaoh deals 7 damage to target opponent, creature an opponent controls, or planeswalker an opponent controls.
7/14/2017 The cards exiled by Nicol Bolas’s first and second abilities are exiled face up.
7/14/2017 You may cast the nonland card exiled by Nicol Bolas’s first ability that turn even if Nicol Bolas is no longer on the battlefield or under your control.
7/14/2017 Casting the card exiled with Nicol Bolas’s first ability follows the normal timing rules for casting that card. For example, if the card is a creature card, you can cast that card only during your main phase while the stack is empty.
7/14/2017 If you don’t cast the card exiled by Nicol Bolas’s first ability that turn, it will remain exiled.
7/14/2017 If you cast a card “without paying its mana cost,” you can’t choose to cast it for any alternative costs, such as emerge costs. You can, however, pay additional costs. If the card has any mandatory additional costs, such as that of Tormenting Voice, you must pay those to cast the card.
7/14/2017 If the card has in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.
7/14/2017 While resolving Nicol Bolas’s second ability, each opponent chooses which cards to exile from their hand. Any opponent with two or fewer cards exiles their entire hand.
7/14/2017 In a multiplayer game, if a player leaves the game, all cards that player owns leave as well. If you leave the game, any spell or permanent cards you control from Nicol Bolas’s first ability are exiled.