No, the existence of God can only be given via practical reason, not a priori pure reasoning as classical philosophy tried to do is what Kant would say
de facto is a legal term, though, which technically means 'in practice, but not by right' and has developed the informal usage by extension
i think the dialogue in the OP sounds funny because they're trying to do the same thing with 'a priori', presumably meaning the thing Klino said, except nobody actually uses that term that way, so it brings to mind the specialized Kantian usage which is out of place
Comments
Though because he's basically Satan, if you had some kind of reverse ontological argument, that would be an a priori reason to distrust him