In the series' backstory, 10,000 years ago in a place that would be modern-day Mexico, it started with a mysterious but powerful race with incredibly long lifespans and the ability to absorb life forces from plants and animals, although they had the disadvantage of being easily disintegrated if exposed to sunlight and thus lived underground instead. Kars, an underground-dwelling humanoid being known as a Pillar Man, created a stone mask which grants immortality by absorbing life energy to conquer the sun (which kills his kind). He slaughtered all but four of the tribe. As the Pillar Mens' bodies were already immortal, they required more power for them to become ultimate beings. In 39 AD, three of the Pillar Men, Kars, Wamuu, and Esidisi, came to the Roman Empire to find a perfectly-cut known as the Kars, Wamuu, and Esidisi developed fighting styles to counter Hamon, an energy with the same properties as the energy from sunlight, and nearly wiped out the Hamon tribe, but the stone narrowly escaped them. Following this, the Pillar Men went into a 2,000-year sleep.