I have a question about The Wall's effect and its duration.

I used its ability to play a Night Watch character as defender from my hand, but then, during that challenge phase, The Wall was discarded by an opponent's event.

My question is: must the Night Watch character i played thanks to The Wall return to my hand at the end of the phase?. After all, the effect that forced him to return to my hand was form a card that's already gone.

Aertes said:

Compare The Wall to the event card Ambush from the Plains. Similar "return to hand at the end of the phase" condition created when you trigger the event and the location ability, right? Well, isn't the event discarded and gone immediately after playing it? So if discarding The Wall from play prevented you from returning the Night's Watch character to your hand at the end of the phase, the character dropped in with Ambush from the Plains would never return to your hand.

Or another example: say you use the location Heart of the Kingdom to give a character +1 STR "until the end of the phase." Before the end of the phase, the location is discarded. Does the character immediately lose the +1 STR, or does it keep it until the end of the phase? It keeps it, right? Because when you triggered the location, you created a lasting effect - and the lasting effect stays for its duration no matter what happens to the original card that created it, right?

In both cases (The Wall, and Ambush), triggering the event or location ability puts the character into play with the "return to hand at the end of the phase" effect already on it. That lasting effect is there no matter what happens to the card you triggered to create the lasting effect.

Just as I feared, Thank you very much.