If you push the Illusion Ritual Spell to level 100, you can speak with Drevis Neloren at the College of Winterhold to get the master magic quest. Inquire about anything new from Drevis to start the quest.
Drevis will offer you the special illusion spell called Vision of the Tenth Eye. The spell allows you to see invisible items/texts for 30 seconds. The spell in question is key to finding the master illusion spell clues hidden in the College of Winterhold.
What you are looking for books containing Master Illusion Texts. Here are all the books locations:
- The first book is sitting on the table inside The Arcanaeum.
- The second book is on the second floor of the Hall of Attainment. Look under the bench close to the stairs.
- The third book can be found in The Midden, under the basement of The Hall of Countenance. Check near an Atronach Forge on a table.
- The final book is on the second floor of The Hall of Countenance. Check on the top of a barrel inside the room near the stairs.
Return the texts to Drevis Neloren in exchange for Spell Tome: Hysteria. This ends the quest, and you can move on to other activities.
Need more help? Here are some Skyrim Guides you may find helpful:
- Alteration Ritual Spell Quest Walkthrough
- Destruction Ritual Spell Quest Walkthrough
- Alduin’s Bane Quest Walkthrough
- Scrolls Guide: Locations, Cost, Effects