An Old-World ruler who governed a pair of opposing Aspects and held them in balance (roughly 39 existed).
“A Traveler's Guide to the Planes” — official lore art.
Sovereigns were the rulers of the Old World, before the Sundering. Each Sovereign governed a pair of opposing Aspects — Light and Dark, Life and Death, Love and Hate — and held them in balance. Roughly 39 are thought to have existed.
You meet several as playable characters: Victus (1st, Order & Chaos), Kumyo Kyo (4th, Reality & Illusion), Amstradath (5th, Life & Death), Armand (8th, Light & Dark), and Apeiron (28th, Infinity & Finiteness).