Like all others, the Aztec culture concluded with a death cult.
It’s nature’s way...
On the plaza in front of the big pyramid, the Aztecs had constructed something they called “the corncrib”, which was filled with stacked human skulls. Cortez et al were horrified, and at some point before they destroyed the whole complex, using measurements they estimated the number of skulls at a quarter million. These were remains of victims from years of various sacrifices, “games”, and what the Aztecs called “flower wars”, in which they’d attack some other tribe and keep attacking them until they submitted and started sending tribute — young males and females for various tortures and death.