The lords of hell rage within the Black Soulstone, their souls screaming for vengeance and release. Before the artifact can be sealed away forever, Malthael–Angel of Death–manifests in the mortal realms with a deadly new purpose: to steal the Black Soulstone and bend its infernal power to his will.

The expansion also accentuates the key features of the Diablo franchise, with a greater emphasis on randomised environments to explore; epic new quests; horrific new monsters to defeat; and substantial updates to the loot experience, enabling players to further customize their characters with new and improved multilevel Legendary items, new Blacksmith and Jeweler item-crafting options, and more.

Diablo III's Paragon progression system is also being majorly upgraded for the expansion, adding even more end-game character advancement and replayability. Two new game modes—Loot Runs and Nephalem Trials— are being added as well, providing fun and rewarding challenges for players to tackle when they're not busy saving the world.

Features:
Charge forth as the Crusader - Impenetrable armor, gleaming weapons, and heavy, heavy damage–wield the power of the Crusader, unbreakable new hero of the mortal realms.
Take Act V by storm - From the sprawling streets of Westmarch to the ancient walls of the Pandemonium Fortress, battle with a host of deadly new enemies throughout the all-new Act V of the Diablo III storyline.
Rise to new heights of power - Advance your hero of choice through additional levels of supremacy, mastering bold new powers of raw, demon-slaying potential along the way.
Conquer new gameplay modes - The new Adventure Mode opens up all of Sanctuary - you can travel to any waypoint in any Act. It also introduces Bounties and Nephalem Rifts, two new game features with boundless replay value.
Discover powerful new treasures - A redesigned loot system improves your Diablo III experience with targeted "smart drops", new and improved Legendary items, and the item-augmenting powers of the Mystic.