The Mages Guild invitation quest is the same for all factions. However, the character change based on the chosen faction.
- Find the mage in question
- Join the Mages Guild
- Complete quest
Head over to the Mages Guild and find the mage in question. Talk to them to learn more about the guild before joining. When chosing to join they will welcome the Vestige and make them a student of the guild and suggest them to talk to Valaste, the Mistress of Incunabula.