The Umbaru are a group of humans who inhabit the interior of the jungles of Torajan in the vast area known as the Teganze. The area is extremely secluded, hence why the Umbaru are rarely seen by foreign eyes.
The Umbaru are divided into many tribes, often engaging in tribal warfare. However, these are matters of ritual and not of conquest, the wars being waged in order that the victors may replenish their supply of raw materials for the human sacrifices that their civilization revolves around. Only those who fall in battle are worthy of sacrifice however.
In addition, the tribes define themselves by their belief in the Mbwiru Eikura, which roughly translates to "The Unformed Land" 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 the lesser physical realm.
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. Unfortunately, there is intense social upheaval among the tribes due to an incident involving their most current war.
Witch Doctor Blizzard Entertainment. Accessed on 2008-04-07