Given that the Sovereign commonly called by the devilish name Mephisto was well known to be the strongest of his kin, why he chose the volcanic barrens of now called Dis as his domain is little known. Perhaps it was the central location between East and West, perhaps he desired seclusion. He certainly hasn’t improved the harsh land in the slightest since he claimed it.
Most of Dis is rough and fairly dry, with land very poor for farming or herding. It’s sustained only on the back-breaking labor of countless slaves either purchased from abroad or captured during its waves of conquest. Slavery supports the mortal population of Dis, but there’s also a significant minority of immortals, who have far more malign uses for the humanoid livestock.
Mephisto’s trafficing with devils was never a secret. It was a valueable benefit in the short, brutal war against Irath in fact. However, those fiends haven’t left in the last century. Quite the opposite, the blood of the slaves seems to bring more every day.
Most merchants avoid going any deeper than they have to into Dis. Often sticking to the coastal cities and avoiding the dark interior of the nation. There isn’t that much to fear for them, in truth. The devils and mortal upper class live in absurd luxury, and the material demands to sustain it are great. Having ships avoid their harbors would mean letting vices go unfulfilled, an unthinkable thing.
Dis’ small army is a terrible foe. Not only are there the devils and their corrupt progeny, but for mortals power comes only at the expense of others, the vicious competition produces cunning and strength in excess. Many turn to wizardry, dark pacts or sharp steel to get what they want, and only those with great proficiency survive. This formidable force has never been allowed to grow dull. Dis has swallowed up its independant neighbours, the dark elven nation of Lanal, the free humans of Khar’Batol, and the tribes of the Red Dwarves in Arak’Vathir. The Sovereign ruling the city-states of Tath was slain by the demon-dragon himself, and his territory claimed. The hand of Dis even reached as far as the great island at the mouth of the Inner Sea, now called Khar’Dis before a rebellion funded by other wary Sovereigns ripped it from Mephisto’s grip.
The ambitions of the old red wouldn’t be stalled by one small rebellion. He certainly couldn’t face the combined might of the other Sovereigns, to whom his expansionist ambitions had become clear, but his pride wouldn’t allow him to cease his campaigns. The other Sovereigns needed to be weakened for Dis to have a free hand, and so a plan was hatched. It was the agents of Dis that threw open the old Irathan portals, to let the demons flood in. Once that uncountable legion had slain or consumed the majority of his enemies, and the numbers on both sides of the battle had dwindled, his own undiminished forces would sweep out and claim dominion of all the East. It nearly worked.
Had the method for closing the portals not been found so quickly by the three Immortal Sons, if the battles had gone more poorly against the demons, if The Rot hadn’t been diminished enough for Felarri to spare its arcane forces, or if the help of Infalis hadn’t been bought, there would have been none to stand in Dis’ way. However, as the Dis invasion forces began to mass in southern Cetheron the battle-scarred nations of the East struck. The battle was brutal, and crowned by a strike at its heart by the Immortal Sons. The mightiest Sovereign was defeated, but not destroyed. With their leader suddenly gone the various generals that didn’t retreat with him fell to the usual habits of Dis, turning on each other for control of the army. By the time the power struggle was settled, however, the only thing left to do was order a retreat.
Mephisto, scarred by the pinnacle of the dragonslayer’s art, the ancient Irathan blade Scalebane, has become reclusive in the last few decades. He broods under the darkened skies of his sprawling domain, rumored to be tormented by wounds that never truly heal. Both the devil-dragon and his highest generals dream of revenge, glory and fresh slaves from the East. It’s only a matter of time before their ambitions come to more than greedy stares across the Inner Sea.