Mictlantecuhtli, Lord of the Ninefold Underworld

Mictlantecuhtli is the skeletal ruler of Mictlan, the underworld of the dead, and the fifth of the nine Lords of the Night, his place at the numeric centre of the sequence matching his standing as lord of the place the dead must cross through in nine stages before reaching final rest, a structure the Nahua underworld and the nine fold night count share, though the sources do not explicitly say one was built to mirror the other. He rules Mictlan alongside his consort Mictecacihuatl, and the Legend of the Five Suns, recorded in the Leyenda de los Soles and related colonial texts, casts him as the keeper of the bones of earlier human generations, the precious bones that Quetzalcoatl travels into Mictlan to steal or beg in order to grind them with his own blood and create the people of the present age, a myth in which Mictlantecuhtli tries to prevent the theft and very nearly succeeds. He is shown in the codices with a skull face, exposed rib cage and clawed hands, presiding over a realm the dead of ordinary causes, as opposed to those claimed by water or in battle, were understood to travel toward across four years of trials. Sahagun's informants describe funeral rites addressed to easing this journey, offerings of a dog to guide the soul and provisions bound with the body, practices that assume Mictlantecuhtli's court as a real destination requiring real preparation rather than a metaphor.

Sources Florentine Codex: General History of the Things of New SpainBernardino de Sahagun; translated by Arthur J. O. Anderson and Charles E. Dibble with History and Mythology of the Aztecs: The Codex ChimalpopocaJohn Bierhorst (trans.)