In the heart of ancient Aztec civilization, a ritual as intense as it was spiritual took place atop the grand pyramids. Priests, viewed as conduits between the earthly and the divine, would perform what can only be described as one of the most daunting religious practices known to history. During these ceremonies, the chosen individual, often a prisoner of war or a volunteer, was believed to be imbued with the spirit of a deity. Laying them on a stone altar, the priests would use sharp obsidian