Ah, almost forhit, our symbol of course is a stylized pictogram of the sun. It stands for the chosens enlightenment and four our pretold claim to rule the land. Everyone else is just shadiws, living in darkness, waiting to be enlightened.
Depending on how politics go, we might make some alliances with other tribes, as long as they believe in our god and his prophet ( me ).
Might send some missionaries to other tribes to spread the word. If anyone comes to us and wants to be chosen, they can take the test right away, without years of slavery. (But if they don't pass they are still to be sacrificed) At best, maybe we can conquer a number of tribes without any bloodshed at all.

Long term, mighr add some structure to society. A single tribe is easier to govern than the whole land, there needs to be a command structure. Probably using local temples and priests, which report to me.

Eventually we might have a standing army, ready to deal with revolts and external threats quickly. At that point hunting and gathering might no longrr wirk, might have to build a palace and have slaves work as farmers. Think ancient babylonia. We would then have to teach the ruling elite some sirt of script for accounting and transferring commands efficiently. But thats in the 7 years and more timeframe.