The Witch Doctor is a voodoo fighter whose origins lie in the Torajan jungles of Teganze, to the south-west of Kurast (which was the basis of Act III of Diablo III). He belongs to the Tribe of the Five Hills, which often engages in ritualitstic tribal battles with two other tribes: the Tribe of the Clouded Valley, and the Clan of the Seven Stones. These battles are used to replenish their supply of human sacrifices. Witch Doctors are very tribal creatures, and believe in self-sacrifice for the good of the clan.
Their belief system is that of the Mbwiru Eikura - 'The Unformed Land' - which states that there is a sacred reality beyond our physical existence, and that they must offer sacrifices to their Gods, who inhabit this 'Unformed Land'. Witch Doctors share an affinity with this veiled reality and through dedicated training and ritualistic practice are able to actually perceive it through something called a 'Ghost Trance'.

Male Witch Doctor concept art.
Most of the residents of Sanctuary actively deny the existence of Witch Doctors, presumably out of fear of the rituals they're rumoured to perform on humans and their ability to raise the dead. However, Abd al-Hazir claims to have actually seen them, as documented in his writings:[0]
"Most believe the fearsome Witch Doctor of the Umbaru race a legend, but I have seen one in battle with my own eyes. And it was difficult to believe, even then. He dispatched his opponent with terrifying precision, assaulting his victim's mind and body with elixirs and powders that evoked fires, explosions, and poisonous spirits. As if these assaults were not enough, the witch doctor also had at his command the ability to summon undead creatures from the netherworld to rend the flesh from his enemy's body.
I came upon this rare display as I ventured deep into the interior of the dense Torajan jungles that cover the southern tip of the great eastern continent, in the vast area known as the Teganze, with the goal of seeking out the tribes that reside there. This area is extremely secluded, and heretofore unseen by foreign eyes. I was fortunate to befriend the witch doctor I saw in battle, and, through him, his tribe: the Tribe of the Five Hills.
The culture of the umbaru of the lower Teganze is fascinating and perplexing to those hailing from more civilized walks of life. For instance, the Tribe of the Five Hills frequently engages in tribal warfare with both the Clan of the Seven Stones and the Tribe of the Clouded Valley, but these are matters of ritual and not of conquest. I had heard tales that these wars are waged in order that the victors may replenish their supply of raw materials for the human sacrifices that their civilization revolves around, and when I timidly asked my hosts more about this topic, I must admit their laughter made me fear for my safety. However, through stumbled attempts at communication of such complex topics as what constitutes heroism and honor in their society, I gathered that only those taken in battle are considered worthy of the ritual sacrifice, much to my relief.
Upon further discussions with my hosts, I discovered that these tribes define themselves by their belief in the Mbwiru Eikura, which roughly translates to "The Unformed Land" (this is an imprecise translation, as this concept is completely foreign to our culture and language). This belief holds that the true, sacred reality is veiled behind the physical one we normally experience. Their vitally important public ceremonies are centered upon sacrifices to the life force that flows from their gods, who inhabit the Unformed Land, into this lesser physical realm.
The witch doctors are finely attuned to this Unformed Land and are able to train their minds to perceive this reality through a combination of rituals and the use of selected roots and herbs found in the jungles. They call the state in which they interact with this other world the Ghost Trance.
Alongside the primacy of the belief in the life force and the Unformed Land, the second most sacred belief of the tribes is their philosophy of self-sacrifice and non-individuality, of suppressing one's self-interest for the good of the tribe. This idea, so foreign to our culture, struck me as something I wished to delve into much more deeply.
Unfortunately, there was intense social upheaval among the tribes due to an incident involving their most current war (inasmuch as I could discern in the ensuing bedlam), and the charged atmosphere warranted my quick departure before I could ask anything further of my hosts."
