New World, Old Rules?

The savage era runs on big fish eating small fish, and the tribe there is kept in hand by a priest with a scheme of his own. Axel is a mercenary at the top of his trade, and an explosion drops him into that world. He wakes up and Mu Lingling, a woman who fights for the tribe, already has him captive. The capture is what switches on a system that offers him mastery of the savage era. What he has and nobody there has is firearms, special-forces fighting and the knowledge of his own century. He drills wood to make fire in front of the tribe and is treated as a messenger of the gods afterwards. One gunshot ends any argument the tribespeople still have with him. Once he has laid out what the priest was doing, he leaves with Mu Lingling for a stretch of cliff that is easy to defend and hard to attack, and puts up a holding there. He takes a saber-toothed tiger apart with his bare hands and brings the other tribes under him.