In 3069, Earth faces annihilation from demonic invaders. Through grafting technology, humans turn the tide at the Battle of the Dawn by using demonic powers against their invaders. Amid this chaos, Aang, the Mightiest Warrior, falls, but his demise isn't the end. Instead, he mysteriously travels 60 years into the future, harboring the ultimate demon power within him—a double-edged sword. To overcome past regrets and uncover the truth, he must continuously "evolve" to control the demon within.