Can Landroval save the players from losing if a saga hero is killed? Or does the game immediately end upon the hero's demise? What about if a player's last hero is destroyed - can Landroval bring back that hero, keeping that player in the game?

Once your last hero is destroyed, or a required hero (or ally) leaves play, you are immediately

eliminated and don't have an opportunity to trigger any response effects.

I would say in this case it's too late; the Response is triggered after the hero is destroyed.

The Response says to place in "back" in play, so presumably it must have left play and therefore killed you.

The Response says to place in "back" in play, so presumably it must have left play and therefore killed you.

The meaningfull word, here, should be "After", and no presence of the word "cancel" who is the only one that can backtrack time.

Once your last hero is destroyed, or a required hero (or ally) leaves play, you are immediately

eliminated and don't have an opportunity to trigger any response effects.

Well I guess what I had in mind was Landroval being under the control of a non-eliminated player.

But you all have confirmed my suspicions, thank you.