I would say that Diabolus Ex Machina
is valid, (Diabolus is antonym to Deus, so it makes sense as the name for an inverted version of Deus ex Machina
,) and that Diabolus Ex Nihilo
is valid as well. (Tt does
literally mean devil from nothing, which makes sense for the Trope, as well as being different enough from the original that its status as a snowclone is debatable.) As for the others, I like Deus Est Machina
, and "est" is close enough to "is" that most people will know what it means, especially from the context of the example. The others are trying to hard and are either puns for the sake of puns, or valid tropes with confusing names.