=== Master Illusionist ===
Once you reach level
100 in [[Skyrim:Illusion|Illusion]], you can ask Drevis if there is anything [[Skyrim:Illusion Ritual Spell|more to be learned]] about Illusion magic. He will respond with: ''"You have gone beyond my teachings, which is quite a feat. I did not think it possible. But there is always more to learn. I believe you are ready for the next step."'' Asking him about the next step, he will say: ''"Knowledge of truly powerful Illusion spells is here at the College, but it is hidden from those who might misuse it. I shall teach you a spell to discern things hidden from others. With it, you will be able to acquire the texts you need. Bring all four to me, and I shall use them to inscribe the spells for you."''
Upon acquiring all of the books and telling Drevis that you have them all, he will say: ''"Yes, very good. Here, then, is the first of the Illusion spells you sought."''