Put target creature into its owner's library second from the top. Its controller gains 3 life.
"'Invincible' is just a word."
—Gideon Jura
(15/06/2010)
Note that the creature’s controller, not its owner, is the one who gains life.
(15/06/2010)
If the targeted creature’s owner has no cards left in their library, that creature is put into that library as the only card there.
(15/06/2010)
If the targeted creature is a token, it will cease to exist after it’s put into its owner’s library.
(15/06/2010)
If the targeted creature’s owner has one or more cards in their library, that creature is put into that library directly under the top card.
(15/06/2010)
If the targeted creature is an illegal target by the time Oust resolves, the spell doesn’t resolve. No one gains life.
