We also believe in a concept of cyclic history, and that's very important to this discussion.
In general, whatever is and whatever will be, already has been. History represents a series of repetitions, with minor variances. The Teteo will be born as human beings, they will live lives, they will die - usually by sacrifice, in one way or another - and they will become Teteo again - in the process gaining Power, Power that's needed to maintain Ollin, which we do not see as self-sustaining.
You have a word, in your time, for the absence of Ollin. That word is Entropy, and that is what we fight against, that is our great enemy...

Xipe Totec, our Lord the Flayed