I loved this story, especially since it talks about the mysterious era of the Warring States. All I want is not to make the main character too strong and to give him abilities that are not just unlimited.
I loved the story, it's great, and I hope you continue to write it, and I will support you, even a little. Also, I wish you would try to give him a special talent without it being because of the system, such as the wonderful control of the ball.