The new guys are the divinely powered Priest and military-focused Commander, bringing the Early Access game's Sovereign roster up to a respectable five.
The Priest focuses on healing and defensive magic, andsuggests that she starts off the game as quite a low-key force, before ramping up to be a real power to be reckoned with in the late game. She can also "reverse the spread of the Sorcerer King’s corruption across the land, buying time before the final confrontation."
The Commander much prefers smiting things with swords. Or, more accurately, getting his armies to do so for him. He packs the most powerful armed forces in the game, but relies less on magic and spells as a result. For those who like crushing resistance under their armoured boots.
Of course, you can pack in as many heroes as you want, but a 4X game lives or dies on its replayability. To that end, beta update three adds random maps for the first time. Alongside the general terrain layout you'll find that quests, monster lairs, remnant factions, and the Sorcerer King’s fortress will all be randomly placed.
Those are the big additions in the new update, but there's also a plethora of bug fixes and balance tweaks. In particular Stardock points out the eradication of a "longstanding bug that has eaten so many movement points of units entering and exiting armies." Hooray. You can check out the full.
Sorcerer King is scheduled to release in full spring 2015.