Xiuhcoatl

Xiuhcoatl (太陽の蛇(シウコアトル)) is the ultimate weapon of the Return of the Winged One, consisting of several surface craft and a satellite, appearing in Toaru Kagaku no Railgun SS: Liberal Arts City.

Etymology
Xiuhcoatl (meaning "turquoise serpent" and also carrying the symbolic meaning "fire serpent") is a serpent in Aztec mythology, regarded as the spirit form of Xiuhtecuhtli, the Aztec fire deity, and also an atlatl wielded by Huitzilopochtli.

Appearance
The Xiuhcoatl crafts are over 100m long, resembling rugby balls forcibly stretched from each end. They have several large and small wings on their back and sides. A large tank is located inside the craft. The main orbital craft has hieroglyphs carved on its side.

Principles
Much like the Mixcoatl, the Xiuhcoatl is constructed from wood, cloth and obsidian.

The Xiuhcoatl can release large amounts of burning liquid from holes on its side, which can spread flames across an ocean's surface. The craft's movements are controlled remotely and it can move at speeds of around 100kph.

The surface craft are capable of opening up to form a parabolic antenna about 200m across, in order to assist the satellite in aiming its orbital bombardment. The orbital bombardment takes the form of thousands of beams of light, which can destroy everything in a 10km radius.

Background
The satellite Xiuhcoatl was launched into space by the ancient Aztec civilization, during a time when they believed in legends that the sun could easily be destroyed, as one of their many projects to protect the sun. Its original purpose was to launch large amounts of flint into the weakening sun, which was meant to act as fuel and restore the sun's vitality. Though it failed to fulfill that role, the Xiuhcoatl was still able to be used to provide orbital bombardment.

Toaru Kagaku no Railgun SS: Liberal Arts City
The Return of the Winged One used Xiuhcoatl during the operation to destroy Liberal Arts City. Four craft were deployed from a converted tanker over 20km from the city and proceeded to fly towards it over the ocean. En route, two of them were attacked and destroyed by Misaka Mikoto and Shirai Kuroko. A third opened up to allow an orbital bombardment to be launched towards the area and was blown away in the attack.

The final craft managed to reach the city, but was attacked before it could reach the middle of the city. Rather than risk it getting shot down before accomplishing its purpose, the operators opened the antenna prematurely, however it was struck by a railgun shot before the orbital barrage could be aimed. Whatever functionality it may have had left was then lost when Xochitl used her Mixcoatl to save Saten Ruiko from being crushed by the falling wreckage.