This isn’t really a religion, but it does come close. This is a combination of philosophy, medical science, and medical theory. For some reason, in Blacksoul, people who develop supernatural powers to heal tend to be the ones who try to follow these teachings.
The writings are all from ancient history, and records of history aren’t very good. People who want to study the Scentia Medicus first become fluent in the ancient tongue. Even though some of the writings are philosophy and theory, all aspects of these teachings seem to be true in the modern day. It’s like one of those things that people knew how to do in the old days, and then the information was almost lost.
Because it’s goals involve making someone a good doctor who saves lives, the Blacksoul government accepts it. To them it isn’t seen as a religion, but rather as something most don’t have the dedication for unless trying to be a doctor. However, even Blacksouls who follow this path seem affected by it’s peaceful and preserving philosophy.
In The Resistance most healers have studied this under a teacher, and then continued independently after. Oddly, most of the healers in that group follow the Scentia Medicus almost like a religion, and develop supernatural abilities to heal.