An illusionist was a mancer who practiced the Art of illusion. Illusions were a frequently used branch of the Secret Art, however, very few ever became master illusionists. The Faellem were widely known for their mastery of illusion and other powers of the mind.
Faelamor was widely considered the most powerful illusionist in the history of the Three Worlds, and was known to be able to use illusions so powerful that she could easily drive anyone insane.