Arthan Griffon had been a monster, but also a genius who had reached an understanding of the healing arts that still baffled even modern mages.
Vastor believed that once he mastered the Madness, he would be able to set the foundations for new branches of Light magic and become a Magus just like Menadion did after improving Silverwing's work.
Alas, there was only so much that he could understand with the few fragments and blueprints of the Madness still available. On top of that, his ignorance about the Forbidden Arts made everything even harder.
To devote all the time that he could to Arthan's Madness, Vastor became a Professor at the White Griffon academy. Improving the teaching textbooks was child's play to him and gave him the perfect cover to look for people who might make up for his shortcomings.