Here's a quote from the players handbook to set the mood of the game.
Once, Zygofer the Spellbinder was one of us, leading the passage through the mountains into the new land. But when faced by the savage orcs, he opened dark gates to seek the help of demons. That was his undoing. Zygofer turned on us and placed himself on the throne of the Ravenland, his daughter Therania by his side.
To keep their vile corruption from spreading, our wise king built a great wall across the mountain pass and forbade all to ever speak of what had
happened. Since then, the Spellbinder’s domain is known as the Forbidden Lands.
To this day, the demon-king and his daughter still rule there. Using the feared Rust Brothers, and the demonic Blood Mist sucking the life out of
anyone who dared stray too far from their hearth, Zygofer and Therania have kept the human folks who still live north of the wall under their heel.
Yet, not all is lost. For now, the Blood Mist has lifted and there are those who dare defy the demon-king and his daughter. Adventurers. Treasure hunters. Scoundrels. Not heroes, far from it, but men and women who dare travel the land as they choose and make their own mark on it, unbound
by any fate or story set for them. They hunt for ancient treasures, they fight whomsoever gets in their way, they build a new world for themselves
on the ruins of the old.
They are the raiders of the Forbidden Lands.
I hope to see you at the gaming table,