This is a simple mod changing the Aztec UA to generate faith from killed enemy units instead of culture, the way it is designed in the Conquest of the New World Deluxe scenario.
The "culture from kills" ability has been completely removed from the Aztecs with this mod, and can now only be gained through adopting the Honor policy tree.
Spoiler screenshot of new Aztec UA :
The mod was designed for and is compatible with the Brave New World expansion. Whether or not it is compatible with Gods and Kings I am not sure, but I doubt it as I believe the faith from kills XML snippet was added with the BNW update that came along with the CotNW Deluxe Scenario.
If you have any comments they are more than welcome in my Minor Mods thread: http://forums.civfanatics.com/showthread.php?p=13828280