[+1]: Look at the top card of your library. You may reveal that card and put it into your hand. If you do, you lose life equal to its mana value.
[−2]: Create a 2/3 black Vampire creature token with flying and lifelink.
[−7]: Sorin the Mirthless deals 13 damage to any target. You gain 13 life.
If you choose not to reveal the card you looked at with Sorin's first loyalty ability, it stays on top of your library.