The concept art of Diablo III: Reaper of Souls show new monsters serving Malthael including the Seraph, the Wraith, and the Brute. Among the images you will find a few iterative concept artworks of Malthael, a Horadrim, and a scene titled “Tomb of Rakkis”.
Now this Tomb of Rakkis is definitely interesting in a few ways. Rakkis was the king that brought civilization to Westmarch, and brought the Zakarum religion to the region.
The Diablo III: Book of Cain says the following about Rakkis.
Westmarch
Founded by Rakkis, Westmarch was named in honor of the Zakarum warlord’s great crusade and marks the farthest western point of his conquest.
Rakkis was loved by the peoples of the west and did much to bring civilization to the surrounding lands, including the building of roads and churches and necessary infrastructure for the burgeoning territories there. In time, Rakkis’ heir Korsikk, continued his father’s rule and built Westmarch into a bastion of the Zakarum faith.
Ever wary of attack from the northern barbarians, Korsikk founded the impregnable Bastion’s Keep to safeguard all that his father had thought to build.
In the present day, Westmarch is a kingdom that thrives on commerce and maritime trade. Influence from the Zakarum faith has waned of late, and Westmarch is now a forward-looking civilization. Indeed, one might say that it remains one of the healthiest, most vibrant kingdoms left in our troubled world.
Now the thing is — Malthael, is now known as the Archangel of Death. He has arrived to Westmarch to begin there his purge of Sanctuary — as he sees humanity as the biggest faction of demonspawn. Malthael is bringing the dead back to life to serve as his minions in the purge of Sanctuary.
The concept art of the Tomb of Rakkis evokes an intriguing question. Will players fight a resurrected Rakkis as an enemy dungeon boss?