Rise from the Ruins

There once was a genius who was as dazzling as the sun. He built a city in the sky, used the energy of the sun to discover talents, and gave them to the world; but the sun is not omnipotent. He used the energy of the sun to combine with animals and learn from mythology and history to study the seven sin beasts. However, the seven sin beasts ran away from the city in the sky and caused harm to the world. The protagonist went through hardships to recover and kill the sin beasts.