Final answer:
The Aztec codices included accounts of supernatural events as warnings of disaster and prophecies of the arrival of the Spanish. This served to justify the Spanish conquest and establish cultural uniqueness.
Step-by-step explanation:
The Aztec codices included accounts of supernatural events preceding the arrival of the Spanish for several reasons. Firstly, the Aztecs placed great importance on signs and omens in their society, and these supernatural events were seen as warnings of impending disaster.
Secondly, the Aztec religious beliefs included prophecies of a white-skinned god, Quetzalcoatl, who would come to the Empire and conquer it. The Aztecs may have wanted to emphasize these prophecies to justify the arrival of the Spanish and their conquest.
Lastly, the Aztec origin story and their belief in coming from a distant land served to establish a sense of cultural uniqueness and superiority.