Every magician is a Magician. The class is what all of them share: a shield, a forcestrike, mental speech, and the small heats and lights of first year. What they do not share is the discipline, chosen at the end of the University years and in play at level 1 as the subclass: Healer, Warrior or Alchemist.
A Magician takes domain cards at or below their level from their discipline's domain, and at or below half their level, rounded up, from any other domain. The class lists every domain so the sheet accepts any card; the half-level cap for the other domains is kept at the table.
Suggested traits in the creation dialog: Agility +0, Strength -1, Finesse +0, Instinct +1, Presence +2, Knowledge +1. Each discipline suggests its own on its page.