Each Avatar’s Nationality reflects what they did during their reign. Fire is the element of power. Avatar Roku’s actions sparked a war in which one nation wanted power over the world. Earth is the Element of substance and stability, which Avatar Kyoshi brought to the Earth Kingdom when she killed Chin the Conqueror. Air is the element of freedom, which Aang brought to the people of the world when he ended the 100 year war. Water is the element of change, which Korra brought to the world by changing bender/nonbender interactions, reuniting spirits and man, and opening a new spirit portal.
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