In the beginning, before anything else existed, there was only the Great Tree — a single seed that contained immense power and from whose branches the world was made. The five purest saps dripping from the Tree absorbed living matter and became five crystal entities called Soulcores, which hatched into five races of mighty Mongens: Celest, Chaos, Beast, Mystic, and Tectos. They lived together as protectors of Monsterra for millennia — until a Chaos Mongen betrayed his own kind, stole the Great Tree's energy to claim supreme power, and shattered Monsterra into pieces before vanishing. The Mongens have searched for the stolen energy ever since. Humans appeared later, learned to live alongside the Mongens, and together they built something new. But deep in every Mongen, the longing for what was lost before humans arrived has never gone away.