If Firestorm Phoenix would die, return it to its owner's hand instead. Until that player's next turn, that player plays with that card revealed in their hand and can't play it.
10/4/2004 It may not be cast again until your next turn, but it can be put onto the battlefield by other effects.
10/4/2004 The “rebirth” is a replacement effect.
10/1/2009 The Firestorm Phoenix you return to your hand is tracked by its ability. As long as it remains in your hand, that particular card can’t be played before your next turn begins, but a different Firestorm Phoenix in your hand can.