From the post:
The Um’Cal Tribe knows all about sacrifice. They’ve had to make many to survive over the years. Life is fleeting, but the Tribe will last through the ages. When one of their own falls in battle, the hate within them boils over. Losing a member would make some Tribes wilt in sadness and fear, but the Um’Cal just get mad.
The Um’Cal feed their rage and take advantage of a berserker energy. They slice through foes with a frenzied efficiency that would impress the great warriors of the past. Corpses pile up, and their lost members only serve to fuel the fire within their souls.