(warning: mild spoilers for the series. Insofar as possible, I’ve tried to define people by their function the first time they appeared)

You can download a character glossary for the Kindle here, courtesy of Nathan McKnight.

SoU: Servant of the Underworld
HoS: Harbinger of the Storm

A
Acamapichtli (Handful of Reeds): High Priest of Tlaloc (SoU, HoS)
Acatl (Reed): narrator, High Priest of Mictlantecuhtli (SoU, HoS)
Axayacatl-tzin: the current Revered Speaker, Emperor of the Mexica (SoU, HoS)

C
Ceyaxochitl: Guardian of the Sacred Precinct, and agent of the Duality in the Mexica Empire (SoU, HoS)
Chalchiutlicue (The Jade Skirt): Goddess of Lakes and Streams; Tlaloc’s wife (SoU, HoS)
Coyolxauhqui (She of the Silver Bells): Southern Hummingbird’s rebellious sister, imprisoned beneath the Great Temple (HoS)
Cozamalotl (Rainbow): student at the calmecac (SoU)
Cocochi: Mahuizoh’s mother (SoU)

D
Duality: supreme deity, residing in the Highest Heaven (SoU, HoS)

E
Echichilli: eldest member of the council; respected magician (HoS)
Eleuia (Wish): the abducted priestess (SoU)
Eliztac: priest of Chalchiutlicue (SoU)
Ezamahual: novice priest in Acatl’s temple (SoU, HoS)

H
Huacqui: disgraced Jaguar Knight (SoU)
Huei: Neutemoc’s wife (SoU)
Huitzilpochtli (The Southern Hummingbird): God of War and of the Sun, protector of the Mexica Empire (SoU, HoS)

I
Ichtaca (Secret): Fire Priest of Mictlantecuhtli’s main temple, Acatl’s second-in-command (SoU, HoS)
Icnoyotl: poet (SoU)
Itzpapalotl (Obsidian Butterfly): Goddess of War and Sacrifice, head of the star-demons (HoS)
Ixtli: warrior of the Duality (SoU)

M
Mahuizoh (of the Coatlan calpulli): Jaguar Knight (SoU)
Manatzpa: member of the council, Teomitl’s and Tizoc’s uncle (HoS)
Mazatl (Deer): toddler, Neutemoc’s daughter; also a child in the Floating Gardens (SoU)
Mihmatini (Prudent One): Acatl’s and Neutemoc’s younger sister (SoU, HoS)
Mictlantecuhtli (Lord Death): god of the underworld, Acatl’s patron (SoU, HoS)
Mictecacihuatl (Lady Death): Mictlantecuhtli’s wife (SoU, HoS)
Mixcoatl (Cloud Serpent): God of the Hunt, Father of Quetzalcoatl (SoU)

N
Nettoni: Xahuia’s sorcerer HoS)
Neutemoc: Acatl’s older brother, of the Atempan calpulli; Jaguar Knight (SoU)
Necahual: priest of Tlaloc; Acamapichtli’s envoy (SoU)
Nezahualcoyotl-tzin (the Fasting Coyote): former ruler of Texcoco, father of Nezahual-tzin (deceased) (HoS)
Nezahual-tzin (the Fasting Prince): ruler of Texcoco (HoS)

O
Ocelocueitl (Ocelot Skirt): High Priest of Huitzilpochtli (SoU)
Ocome: councilman (HoS)
Ollin (Movement): baby, Neutemoc’s son (SoU)
Oyohuaca: slave girl in Neutemoc’s house (SoU)

P
Palli (Shield): offering priest at Acatl’s temple (SoU, HoS)
Papan: student at Zollin’s calmecac (SoU)
Patecatl: God of Medicine (SoU)
Pezotic: councilman, Master on the Edge of the Water (HoS)
Pinahui-tzin: magistrate at the Imperial Palace (SoU)
Popoxatl (Strength of Water): a child in the Floating Gardens (SoU)

Q
Quechomitl: one of Neutemoc’s slaves, usually on guard duty (SoU)
Quenami: High Priest of the Southern Hummingbird (HoS)
Quetzalcoatl (the Feathered Serpent): God of Creation and Knowledge, son of Mixcoatl, traditionally opposed to Tezcatlipoca (SoU, HoS)
Quiyahuayo: Jaguar Commander (SoU)

S
She-Snake (Tlilpopoca-tzin): vice Emperor of the Mexica (HoS)

T
Tezcatlipoca (Smoking Mirror): God of War and Fate, and of sorcerers (SoU, HoS)
Teomitl (Arrow of the Gods, Ahuizotl): a young warrior at the boys’ calmecac (SoU, HoS)
Tizoc-tzin: Master of the House of Darts, heir-apparent to the Mexica Empire (SoU, HoS)
Tlaloc (The Storm Lord): God of Rain and Abundance (SoU, HoS)
Tonatiuh (The Fifth Sun): incarnation of Huitzilpochtli as the Sun-God (SoU, HoS)

U
Ueman: Fire Priest, second-in-command of Quetzalcoatl’s Wind Tower in Tenochtitlan (HoS)

X
Xahuia: princess from Texcoco, Axayacatl’s wife (HoS)
Xochiquetzal (The Flower Quetzal): Goddess of Beauty and Love (SoU)
Xochipilli (The Flower Prince): Her Consort, God of Youth and Games (SoU)
Xoco (Fire): Mahuizoh’s wife (deceased) (SoU)

Y
Yaotl (Enemy): Ceyaxochil’s personal messenger (SoU, HoS)
Yolyama: guard in the Jaguar House (SoU)

Z
Zamayan: son of Xahuia (HoS)
Zollin (Quail): priestess in charge of the girls’ calmecac (SoU)