The War against Eldus
Pompeii, the leader of Machina, had a vision of bringing together the different species across the continent to guard Monesis and create a world of peace and harmony.
However, a new species appeared without warning -- Eldus. Coming from distant corners of the universe, they considered recording history and exploring their origin their ultimate mission.
Since they had discovered that Monesis was closely related to their origin, Shamash brought other Eldus to Continent Tarones and requested for Monesis from Pompeii, who rejected her.
To bring back the mother of her species, Shamash waged wars against Machina, and stirred up conflicts across the continent. The forbearance of Machina had only worsened their situation, and they were eventually defeated by Elduses and their allies.
Invaded by Eldus, Machinas had no choice but to seal Shamash along with the entire Mech City in order to protect Monesis and everything in the universe.
But this was far from the end. The eldus, Enlil, had replaced Shamash and become the new leader who perpetrated a bloody massacre on Continent Tarones.
The Runedragon Cang Bi, however, was a friend of Machina. Inheriting the spirit of Pompeii, it planned to form an alliance to retaliate.