I’m gonna be honest, I read the wiki to try to figure it out and it’s kind of a mess. I’m with you.
Unlike the other courts, Vantress has no official ruler. Instead, the people of Vantress are led by the Magic Mirror, Indrelon, itself. However, as it is a sentient magical object that spends most of its time underwater, most of the day-to-day responsibilities tend to fall on one or two notable Vantress loremages under the title of archmage. It takes a sharp mind to earn the Mirror's respect and decipher its cryptic instructions, so the position of archmage is regarded with a level of respect reserved for the monarchs in other courts. Gadwick is the most recent archmage of Vantress.