Let me play for a moment and unpack what this could mean, since you've found it interesting:

Someone is actively looking for a person (or an AI, or a role) willing to argue the unpopular, contrarian, or morally difficult side — across all categories of discussion. Politics, ethics, science, relationships, art, technology… no topic is off-limits. The hyphens might indicate a specific search syntax (e.g., on a vintage search engine, Usenet, or a database).

The devil's advocate ( advocatus diaboli ) was the Vatican official who argued against a candidate's sainthood to test their case. So the poster could be searching for the method of rigorous doubt — not a person, but a perspective — applied universally. Why? Because they suspect groupthink, blind consensus, or missing nuance everywhere.