The way that terrible dudes have ruined the phrase Devil’s advocate really irks me, because the origin of the phrase is amazing.
Back in the day, when someone was up for potential sainthood, the Catholic Church would put the stiff on trial.
Each side of the case would be assigned to an actual, accredited lawyer (who was, of course, also a priest, so it’s sort of a priest/lawyer multiclass deal).
One of them would take up the role of God’s advocate, and argue in favour of the candidate’s canonisation.
The other would take up the role of the Devil’s advocate, and argue that the candidate was just a regular asshole and didn’t deserve it.
So in its original sense, the term isn’t at all metaphorical. The Devil’s advocate is literally the Devil’s representative in a court of law.
Which is a. awesome, and b. all kinds of messed up, if you think about it from the perspective of the priest who gets stuck with the job. You’ve devoted years of your life to becoming a priest and an expert in Church law? Good job – here’s your first case. Your client is the actual Devil.