10,000 years ago.
Earth faced the greatest danger to its existence.Dertgotz, a fallen angel who once was a celestial god, was expelled because of his greedy, cruel nature.He marched into the human world with his army of evil.Many lives were lost and much of the land was destroyed. Slowly yet surely, the human world was consumed by Dertgotz's inconceivably vast and evil power.

The war(War of Angels Gold) for survival against Dertgotz continued for many years.
A human hero eventually appeared, and grew powerful enough to rival Dertgotz's might with the help of his trusted comrades.After a long and perilous journey, this hero and his comrades were finally able to defeat Dertgotz and his evil soldiers.That hero was the legendary Euclid.

Euclid realized that nothing could kill Dertgotz.

His only solution was to seal away the fallen angel in his magic sword.

Thinking that this wouldn't be enough to protect the world from Dertgotz, Euclid built the Tessarium and thrust his magic sword in its lowest level where it would be safe. He then divided the only key to the Tessarium into 4 pieces, and gave them to four legendary dragons to act as guardians of the key fragments. These guardian dragons brought their key fragments to four different shrines on the continent, and each shrine was protected for generations by four priest families. Dertgotz, however, was too cunning and took measures to revive himself someday in the future. Before he was sealed by Euclid, he secretly divided himself into two, and left half of himself on the Earth. Since his separation, Dertgotz's remaining half has waited a long time to free the rest of his essence from Euclid's seal. So soon, 10,000 years have passed.