If you would draw a card while your library has no cards in it, you win the game instead.
+1: Target player puts the top two cards of their library into their graveyard. Draw a card.
-8: Draw seven cards. Then if your library has no cards in it, you win the game.
Quote from comprehensive rules »120.4. A player who attempts to draw a card from a library with no cards in it loses the game the next
time a player would receive priority. (This is a state-based action. See rule 704.)