A thousand years ago, the ancient demon king was besieged by the seven major sects, and his residual elixir was made into an insect-king vessel. The sects built the Ten-Thousand Demons Insect-Feeding Tower, using prisoner beasts to cultivate the demon god elixir, attempting to break through their cultivation levels. Amnesiac youth Ling Yuan, who is precisely the vessel of the demon king's reincarnated residual elixir, awakens at the bottom of the tower. When intercepted and hunted down, he awakens the Myriad Spirits Devouring Dao. To explore his life experience, he embarks on the path of climbing the tower, making companions, and growing through battles level by level. As he climbs layer by layer, millennial secrets are gradually unveiled. The demon king's death had other plots behind it, and the insect-feeding tower conceals the heavy responsibility of resisting outer-heaven black shadows. Ling Yuan breaks free from his fate as a chess piece, rallies all spirits, and overturns the millennium chess game set by the seven major sects.