The Tomb of the Nightmare-King

So, because I have promised to review some 5e tools (particularly a character record/designer) and because the normal 2e game didn't go forward this week due to family obligations and illness, we have undertaken to playtest the D&D Next rules. This is the setting we'll be using.

The Empire of Oroylus
This ancient and decadent empire now heaves its final death throes as corruption runs rampant through its body. It is riddled with the cancers of factionalism and deceit. Emperor Voemydas rushes hither and yon to suppress rebellion, execute traitors, and bring the avenging arm of the imperial court to the far corners of his massive and decaying land. Barbarian tribes gnaw the empire from without, invited by corrupt regional commanders to serve as mercenaries in her internal wars. Oroylus, golden, ancient in magic and wickedness, dreams even as she dies.

The Marchland
In the dismal easterland of the empire is the vast Marchland, bordering the muddy Steppe of Bogros. This is the frontline in the failing empire's war with all the kingdoms and peoples of the east; from here, mounted orc tribes pour down Gullet Pass and lay waste to the farmlands of the March. Powerful regional lords, the Marchions, rule their fiefdoms with absolute power.

The Tomb of the Nightmare-King
Three hundred years ago, when Oroylus was young and King Oroy was its ruler, the fledgling kingdom stood against a vast and awful foe: Böenthal the Nightmare-King, a sorcerer out of some forgotten hell, who threatened to drown the world in his dark magic. Only a coalition of Oroy, the wizard Vathas, and the mighty hero Aeschl, could bind the Nightmare-King. When the reign of Böenthal was finally ended, the great treasures and vast contingents of slaves that made him mighty flooded into Oroylus and the Empire was begun.

But Böenthal was made of more than mortal stuff. He could not be slain, but merely imprisoned in an elaborate and awful tomb, built over his royal palace. For three hundred years, the tomb has remained sealed and safe; the Imperial Scholasticon, the high league of wizards, ensured its safety with inspections and regular increase in the wards which bound Böenthal the Eternal.

Last year, a foolhardy group of adventurer-mercenaries, seeking plunder, drunkenly pierced the outermost veil of the Nightmare-King's tomb. Since Voemydas and his sorcerous allies are busy on the far side of the empire, no one has done anything to re-seal the seeping evil... and now it begins to stir.

Argull
The town of Argull is a little Marcher village just south of Gullet Pass. It has remained on the fringes of the Marchland since the Fall of the Nightmare-King. Now, it serves as the jumping-off point for adventurers seeking the legendary magic and treasures imprisoned with Böenthal the Eternal in his shadowy grave.