Complex sentence: Tlacaelel changed that, he wanted to give a sense of purpose to the Aztec people, he reformed their religion so the demand of sacrifices was constant and the honor and the welfare of a warrior was proportional to the number of prisoners he could take.
Split into simpler sentences: Tlacaelel changed that; he wanted to give a sense of purpose to the Aztec people. He reformed their religion so the demand of sacrifices was constant and the honor and the welfare of a warrior was proportional to the number of prisoners he could take.