The Illusionist Class was a unique variation of the Mage advancement path.
However, unlike typical Mages, which interacted with Mana to formulate spells of varying kinds, Illusionists employed a special kind of magic inaccessible to most, unless they stumbled upon an opportunity to build a relationship with those skilled in Spirit Manipulation.
Seeing as the Wykins were a race capable of awakening the Spirituality Hidden Attribute within Kieran, it wouldn't be too far-fetched to believe that they were capable of such a feat.
After all, while rare, it wasn't difficult to accomplish.
As Kieran looked at the effects of Agatha's illusion, he glanced in her direction momentarily. "Their state is quite interesting. Can you tell me more about what you did?"