All Just A Lie

That'll teach you to believe anything.

When some portion of the story turns out to have never really happened. All Just A Lie, similarly to Plot Ex Machina, isn't really an UnTrash that can be directly played — there are other UnTrashes nested in it, such as All Just A Dream and Story. Essentially, an All Just A Lie-type UnTrash is one that effectively undoes a part of the story, let it be a bit of it or the entire thing, by having it be revealed that the undone story parts were fiction within fiction that was being told to us. It's possible for All Just A Lie to be killed by another All Just A Lie UnTrash by making the first lie that much less canonical. An example of this happening would be All Just A Dream playing in what appears to be a legitimate part of the overarching story, but turns out to be All Just A Story someone is telling an audience of listeners. Therefore, All Just A Dream is unplayed because the story it was a part of wasn't the franchise's canon, thus making the UnTrash itself pertain only to the story the in-universe character was telling.

UnTrashes that don't begin with "All Just A" can play All Just A Lie in the correct context. Time Travel can send the story back to a point before it began, undoing the events after that point as they never happened. What the audience viewed before Time Travel played is now essentially a peek at What Could Have Been. Reset Button is another partial instance of All Just A Lie, but it typically relies on other UnTrashes like All Just A Dream to be played.