Tezcatlipoca

Tezcatlipoca (テスカトリポカ) is a Magic God of Aztec Mythology and a member of the true Gremlin, first mentioned in Shinyaku Toaru Majutsu no Index Volume 13.

Etymology
(often translated as 'Smoking Mirror' from Nahuatl) is a major god in Aztec Mythology, associated with obsidian, the night, jaguars, sorcery and strife, among other things. He is said to have cooperated with Quetzalcoatl to create the world from the body of the monster Cipactli, losing his foot in the process. He is also said to have acted as the First Sun but was knocked from the sky by Quetzalcoatl and destroyed the world in anger, in the form of a jaguar. He also caused the ends of the three following worlds before the current world and the Fifth Sun.

Appearance
Tezcatlipoca is a brown man with dark-colored hair in dreadlocks and a black, polished round mirror in place of a leg.

Personality
Tezcatlipoca's full personality isn't known, but he has displayed signs of personality traits typical of Magic Gods. He is described as one with enough power to create a world but who uses it instead to mercilessly spread and make human sacrifices.

Background
Rather than being the original Tezcatlipoca of Aztec Mythology, who fought Quetzalcoatl for the throne of the gods and lost, this Tezcatlipoca was created in the 16th century, in order to fight against who was mistaken for the original Quetzalcoatl. The exact events which unfolded aren't known, but the Aztec empire fell to the Spanish and at some point, Tezcatlipoca joined the true Gremlin.

Magic God Invasion Arc
At some point around the time of the incident instigated by the High Priest, Tezcatlipoca encountered Kamisato Kakeru and was 'exiled' by his World Rejecter.

Salome Arc
Tezcatlipoca remains exiled, but his likeliness was used in a bluff by Kihara Yuiitsu while fighting Kamijou Touma, Salome and Misaka Mikoto, making use of Sample Shoggoth and an attenuated St. Germain virus to make imitations of the Magic Gods and their magic, to make them think she could draw out the Magic Gods and their power after stealing World Rejecter from Kamisato Kakeru.

Kamisato Rescue Arc
On December 9th, after Kamisato Kakeru himself fell victim to the World Rejecter's power, Tezcatlipoca was among the Magic Gods who beat him up shortly after his arrival in the 'new world', though they didn't kill him. At that point, he and the rest of Gremlin were content to stay in the isolated world, but were keen for the new arrival to leave as soon as possible. A destructive struggle between Gremlin occurred when Nephthys and Niang-Niang decided to protect the boy against Tezcatlipoca and the Magic Gods who sought to continue the punishment. During the battle, he went into orbit and threw spears at the trio as they were riding the Windowless Building, explosively changing the world's geography as the spears hit the surface, before being knocked down to earth by Niang-Niang, ending Proserpina's artificial ice age.

Abilities
Being a Magic God, Tezcatlipoca is powerful enough to risk destroying the world with his mere presence unless precautionary measures are taken. Even weakened by Aleister's spell, he is still capable of destroying the world.

As a sun god and creator of fire, Tezcatlipoca can use heavenly spears of light with destructive power far exceeding nuclear weapons, creating dome-shaped explosions on impact, capable of swallowing up countries and changing the world's geography. As well as the "god of sun" (太陽神) aspect, he also has the aspect of a "god of " (死神).

Character Art Design
According to Haimura, there weren't any particular details focused on in the designs of Tezcatlipoca and the Magic Gods whose appearances were shown for the first time through Yuiitsu's fabrications, given their lack of mention in the story.