The main character is called Tianci. I don't remember his surname. It's about him joining the army.

The main character is called Tianci. I don't remember his last name. It's about him joining the army. He remembered two scenes. One was when his childhood friend gave him a martial arts secret manual before he joined the army. After practicing it, he could see at night and set six targets at the same time. Second, he later fought with an international mercenary organization called Big Dipper, and in the end, he discovered that Big Dipper's boss was a spy on our side. That's all I remember. If anyone remembers, please tell me the title of the book. Thank you!