Envee
A primordial evil brought from outside the world, drawn by the accumulation of wealth.
Envee was one of the four demon lords who assaulted the realm during The War of the Rift, and was successful in defeating the assembled defenders and escaped into the world.
From its lair deep under the seas of Dargarth, Envee's corrupting magics infected the Sauhagin and drove them to attack every nation repeatedly, razing towns and villages and stealing everything they could loot for their demonic master.
Envee was defeated and driven from the world during Siege on the Sunken Citadel, though the rift left in the wake of Envee's destruction dramatically reshaped the lands of the eastern islands, revealing several land bridges as the water of the seas receded.