Every time I create a sovereign (which is frequent, I like to fiddle with them each time I start a game), I keep thinking there should be a talent that unlocks 3rd-level magic mastery. Normally a sovereign can start with either level 1 or 2 in the various schools of magic; I propose a talent - say "Focused Study" - which costs 2 talent points and allows tier 3 magic mastery to be available during sovereign creation. Perhaps the talent could also grant a unique universal spell.