Awaken the Sky Tyrant

Oracle Text

When a source an opponent controls deals damage to you, sacrifice Awaken the Sky Tyrant. If you do, create a 5/5 red Dragon creature token with flying.

Card Rulings

11/4/2015 If Awaken the Sky Tyrant isn’t on the battlefield as its ability resolves, you can’t sacrifice it. You won’t get the Dragon in that case.
11/4/2015 Awaken the Sky Tyrant will trigger once for each source an opponent controls that deals damage to you, but you can sacrifice it only once.