Ous, the city above the clouds, stands on the clouds and is built around the heart of the cloud spring. The four major races have inhabited it for generations and believe in Oceanus, the god of water of life. In this mysterious floating city, civilization develops rapidly and all ethnic groups coexist harmoniously. However, peace did not last long. Invasions of dragons and harassment by monsters occurred frequently. The adventurers in the clouds established a guild to unite and protect their homeland. Adventurers choose professions based on racial advantages: mage, swordsman, spearman, archer, gunner, mechanic, assassin, berserker, priest, etc., accept tasks, and obtain rewards. Every year, Oos holds an adventurer competition to select the strongest hero king to resist the attacks of the dragons and become the top guardian force. For thousands of years, the city above the clouds flourished under the protection of heroes, until one day - the sky shook, the barrier cracked, and the...