How do you think could we get Western Christianity (e.g. Catholicism or something equivalent in this timeline) to have a separate category of priests similar to the Shadow Priests of the Warcraft universe?
There would be two kinds of priests: Light Priests or simply called Priests who are pretty much the same people as priests are in OTL, although less likely to be the fire-and-brimstone type and more likely to preach about the importance of positive emotions and mental well-being.
The other type is Shadow priests. They are people who belong to the church but are usually shunned from society, having a status similar to executioners. Their religious duty is to spread despair, doubt, fear and a "Memento Mori" sentiment among the people. They are known to practice rituals forbidden by the Church, such as blood magic and necromancy and to occasionally aid criminals.
They wear tattered dark robes and carry around an incense burner emanating sulfur and other foul smells. They have mutilated their appearance to appear more gruesome and are known to be excellent psychological manipulators with strong mental discipline, although they usually develop many mental disorders through their lives and are teetering on the edge of insanity. A shadow priest can easily convince a naive and weak-willed person to commit suicide.
Various European governments tried to abolish them but to no avail.
Due to an early Gnostic and Manichaean influence, Christians in this timeline believe that the material world is inherently evil and is born from the Shadow. Thus, Shadow priests are simply priests who remind people of the futility of worldly existence and the dark side of life.
Shadow priests hold a view of themselves similar to Calvinism. They know that they have almost no chance to enter Heaven because of their depravity, but still believe in God's grace, though they have no hope.
How plausible do you think is it for Christianity to develop this way? How would the future of the world develop in this TL?