The Deux Ex Machina is an enemy in Final Fantasy IV -Interlude-. The player fights it after a trio of Android Soldiers merge into one. The Deux Ex Machina opens the battle with Beam, reducing the party to critical health, after which Edge attacks with Blitz and joins the party.
Deus ex machina is a Latin phrase translating as "god out of the machine." It refers to a convention in Ancient Greek plays where an actor playing a god would rise onto the stage on a lift or be lowered from a crane, and would resolve the plot in a favorable manner. "Deus ex machina" thus refers to an sudden and/or improbable character or event occurring near the climax to resolve the plot.
In modern usage, machina may be omitted as implied.