Avatar: The Last Airbender

A century ago, the young Avatar Aang, afraid of his new responsibilities, fled from his home and was forced into the ocean by a storm and encased himself in suspended animation in an iceberg near the South Pole. Shortly after, Fire Lord Sozin, the then-ruler of the Fire Nation, launched a world war to expand his nation's empire. Knowing that the Avatar must be an Air Nomad, he carried out a genocide against the Air Nomads with the help of a comet enhancing firebenders' power. One hundred years later, Katara and Sokka, teenagers of the Southern Water Tribe, accidentally discover Aang and revive him.