Demon Cultivator from Another World: I Beat the Brave with My Soul Flag

I am a demon cultivator, and I am prosperous in the world of cultivation. Suddenly one day, my brother dressed as a woman stabbed me in a different world. In order to go back and take revenge, I accepted the task given by the goddess to kill the brave men of Nanbo in the other world. So I carried the soul flag and the long sword, and went to the other world to become the son of the demon king. But as soon as I landed, my demon king dad was treated as a brave man and gained experience. Let's see how I can control my subordinates and kill powerful enemies in the beginning of hell.