- When Gift of Isha puts a card into play, there is a delayed effect on that card to discard it at the end of the phase.
- When the card leaves play, all lasting and delayed effects on the card end.
- If the card returns to play in the same phase, it is considered a new instance of the card; lasting and delayed effects from before it left play are not reinstated.
- So, when Fall Back! returns the unit to play, there is no "discard at the end of phase" delayed effect on the card.
Another application of this fact that all lasting and delayed effects end for a card that leaves play:
- Play Empower of Planet X.
- An "Empowered" Eldar unit at Planet X is destroyed, and the bonus from Empower ends for that card.
- You use Gift of Isha to return that unit to Planet X.
- The returned unit no longer receives the bonus from Empower (because it left play and so is not considered to have been at the planet when Empower was played).