Xingtian Slayers
At the summit of the Three Realms, Martial Ancestors represented the peak of the cultivation path, all revered as entities that stood above the heavens. Martial Ancestors could live for one billion years, and due to their unique powers, typically couldn't be killed by anyone below the Martial Ancestor realm.
The entirety of the Celestial realm didn't have over 12 Martial Ancestors, with the majority belonging to the Immortal race. Even the Heavenly Emperor, reputed as the most powerful active God of the Celestial realm, was still stranded at the peak of the Martial Sage realm—far from becoming an ancestor.
With Taotie's accumulations, she could indeed break through. After all, the 300 demons she absorbed were originally all Martial Emperors. The Tribulation Qi they accumulated during the Heaven Rejecting Blood Ritual was enough for Taotie to take the final step and become a Martial Ancestor.