The Sun Warriors are the people of the ancient civilization who first discovered firebending from the dragons. The precursors to the modern-day Fire Nation, most of the rest of the world believed they had died out thousands of years before the Hundred Year War. They are still alive, however, and live in secrecy near the ruins of their once-thriving city, where they retain the cultural and philosophical traits of the original Fire Nation people.
The Sun Warrior civilization is one of the earliest known firebending cultures, and predates the Fire Nation by thousands of years. Because of this, their philosophy regarding firebending is pure and uncorrupted, based upon the life-giving and creative aspects of fire. As their name suggests, they draw the power of their firebending from the sun's energy, focusing on physical heat as well as spiritual enlightenment and idealism.
The Sun Warriors also revered and guarded the two great firebending masters, Ran and Shaw, two dragons, one red and one blue. These dragons passed on the secrets of firebending by breathing a multicolored flame over those they deem worthy.
The Sun Warriors developed all of the original firebending forms, such as the Dancing Dragon, but their philosophy is radically different from the present-day Fire Nation. While most consider firebending to be an instrument of destruction fueled by rage and hate, the Sun Warriors believe it represents life and energy, as if there is a sun within every firebender. They are keepers of the Eternal Flame, a great fire that is said to be the first given to mankind by the dragons.
The Sun Warriors prefer to keep their society secret from the outside world; therefore, anyone who discovers their tribe and is deemed worthy to be taught the nature of firebending is instructed to never reveal the existence of the tribe to anybody else. Aang and Zuko kept their word, seeing that while they did mention the form of firebending they learned, they made no mention of the supposedly lost civilization.
The culture of the Sun Warriors may be partially based on civilizations from ancient pre-Columbian Mesoamerica, including the Aztec, Incan, and Mayan empires. These civilizations were sun worshipers and careful observers of astrological movement. The architectural framework from these empires resembles one of the first buildings shown in the Sun Warriors' ancient city.
The entire conceptual schema of the Sun Warriors, their "lost city", their civilization, and their practices bear resemblance to the works of Robert E. Howard, the creator of Conan the Barbarian. Numerous nods to Howard's oeuvre can be perceived throughout the series.
The Sun Warriors are heavily inspired by Southeast Asian cultures.
The primary ziggurat in the Sun Warrior compound bears a striking resemblance to the Candi Sukuh in Indonesia. Step Pyramid style ziggurats also exist in Mesopotamian and Mesoamerican architecture.
The Sun Warrior compound includes architecture inspired by other Southeast Asian landmarks such as the Angkor Wat and the Phanom Rung.
The tribe's clothing is reminiscent of traditional Southeast Asian warrior attire, particularly the headdress of the leader, which resembled Iban feather headdresses, and their pants resemble the Indian dhoti.
The Sun Warriors' chants at the Dragon Ceremony sound similar to the chants at the end credits of Avatar.
The way most Sun Warriors wear their hair resembles Zuko's ponytail in the first book.
Uncle Iroh had previous knowledge of this tribe, and it was the origin of his nickname, "The Dragon of the West".
Despite their isolation and secrecy, they have a surprisingly high amount of knowledge of current events.
They are some of the only firebenders shown whose bending had not been distorted by rage and hate like the firebenders during the Hundred Year War.