All Just A Lie

That'll teach you to believe anything you hear.

All Just A Lie, similarly to Plot Ex Machina, isn't really an UnTrash that can be played — there are other UnTrashes nested in it, such as All Just A Dream or Story. Essentially, an All Just A Lie-type UnTrash is one that effectively undoes some portion of the story, let it be a little bit of it or even the entire thing, by having it be revealed that the undone story parts were "lies" that were being told to us.