Advocatus Diaboli

Advocatus Diaboli, the "devil's advocate," is a popular title given in the Roman Catholic Church to the Promoter of the Faith, an official of the Congregation of Rites (part of the Curia Romana (comprising the administrative institutions within the Holy See). The duty of the Advocate is to raise and urge every possible argument against the documents and testimony adduced in favour of a candidate for beatification or canonisation to sainthood.

The office was established in 1587 during the reign of Pope Sixtus V. The first formal mention of such an officer is found in the canonisation of St. Lawrence Justinian under Pope Leo X (1513-1521).

Speculation exists that such entities exist that are associated with Asmodeus and other Dark Lords, but such hasn't been attested by credible sources. The purpose of these entities would be similar to that of the Catholic Church — that they would act as an adversary, cautioning intervention into world affairs or suggesting means by which evil might potentially triumph through the accomplishment of acts that would go against the Devil's nature.