Avatar Roku is a character from the animated television series Avatar: The Last Airbender. He is the Avatar before Aang, the main character, and is known for his wisdom and powerful firebending abilities. Roku is a member of the Fire Nation and played a crucial role in maintaining balance in the world during his lifetime. Roku's story is explored through flashbacks, revealing his struggles against the rise of Fire Lord Sozin and the impact of his decisions on future Avatars. He serves as a mentor to Aang, guiding him in his journey to master the four elements and restore peace to the world.