Everyone’s heard of the gory human sacrifices of the Aztecs to the gods. But we tend to forget they offered their own blood to the deities, too.
According to Mesoamerican mythology, the Sun dies of old age, along with every era. However, the belief was that this process could be slowed through bloodshed. The Sun gives life but also demands it in exchange, so the Aztecs sacrificed themselves and others to survive.