The Goddess Descends from the Mountains
Mbaba Mwana Waresa was a fledgling goddess, who in Berengar's past life was worshipped by the Zulu. However, the Zulu culture had not yet been established in this world, and because of it, she was not yet worshipped in any significant capacity. At most, a few small tribes would worship her by another name.
As with most deities she was aware of the natural progression of the timeline, at least in her sphere of influence, and upon hearing that the white man had arrived in south Africa centuries before they were supposed to invade and colonize the region, she became fearful. Especially when she heard that a man with a deity's boon was leading them. This meant that some deity from a foreign land had broken a taboo, and brought forth a being from another world to interfere in this one.