Disciple of the Demonic Source: the Mystery of Another World

My destiny is up to me, not to God. He was born in a remote town and had a miserable life. He was not complacent because he had the source of chaos. He worked hard to cultivate, just to save his mother. In the process, he met a girl from the earth. In order to help her find the mystery bead, he traveled to all continents, only to find out that she was not the only one from the earth, and these people had developed their own power here. Some people forged robots, mechanical tools, weapons, some trained ninjas, established a special assassination agency, and some taught how to kill people by playing the piano.