It's been 8 years since Tagon was enthroned as "the Reincarnation of Aramun". Eunseom, who united 30 clans of the Ago Tribe and became "the Reincarnation of Inaishingi", heads to Arthdal to wage a great war against Arthdal. Then, Aramun's tomb and identity from 200 years ago are revealed, along with a prophecy. "When the Sword of Aramun appears in the Zelkova tree, Aramun will know his mission." The conflict between Eunseom, who can never become Aramun, and Tagon, who announced himself as "the Reincarnation of Aramun" and is put to the test again increases. Tanya, Saya, and Taealha repeatedly unite and split forces. Eunseom and Tagon head toward the final battle! Who will become a legend and an eternal song? Some flashing lights sequences or patterns may affect photosensitive viewers.