Oos, the city above the clouds - a city built around the center of the spring above the clouds. The four major races that have lived here for generations all believe in Oceanus, the god of water of life. The civilizations of various races live in this quiet and peaceful place. The mysterious city on the clouds, Oos, is developing harmoniously and rapidly. In this era, people are often attacked by dragons and harassed by other monsters. The adventurers of the City on the Clouds work together and form an Adventurer's Guild to work together to protect their homeland. Adventurers will choose specific professions based on their racial advantages: wizards, swordsmen, spearmen, archers, gunners, mechanics, assassins, berserkers, priests, etc., accept foreign missions and receive generous rewards. Os will hold an adventurer competition every year, selecting the strongest people of each class and conferring them the title of King of Heroes. The King of Heroes made great contributions to O...