For the doctor's training, they used spiritual arrays that simulated living beings, in which the expert would apply his techniques to accomplish specific goals. For example, treating an intestinal wound, stopping bleeding, removing a poisonous substance from the bloodstream, etc.
Such arrays created these simulations, which could be seen as illusions, used to train the understanding of these specialists.
There was a method behind each technique that would result in the treatment of a given anomaly. However, even considering the different ways of solving such problems, the final result and some conditions would have to be obtained.
And that was the purpose of these arrays. Increase the proficiency of these cultivators in certain situations.