The Sundering: Rise of the Witch King is a mod for Medieval 2: Kingdoms and based around the fantasy world of Game workshop's Warhammer universe during the civil war between the Elves, the mod's campaign opens with the Death of Bel Shanaar in -2751 IC.
At the heart of each tomb of the mightiest kings there lies a casket, inscribed with hieroglyphs of malediction. Within this sarcophagus reside the tormented souls of those who have incited the Tomb King's wrath. Powerful binding inscriptions ensure that these souls cannot leave their prison until the moment when the casket is opened. The Casket is not carried into battle; rather it is summoned from the ground, emerging atop a pile of skulls and a dais of bone. Liche Priests nearby may use the power of the Casket to enhance their spells, though it's true power is only revealed when the lid is removed and the contents finally, and fatally, revealed.