Trying to find any other title

Seen a novel on LeReader app that's similar to the God Of War novels but still different in its own way. The novel on that app is called "medical, martial, kingly son in law" does anyone know any other name for it as can't find it anywhere and that app is stupidly expensive for the novels (£9 per 30 chapters o.O...)

The main character is called Xu Nan, starts with him as the main commander waiting on the surrender of his countries enemies when he receives word his sister is in hospital and is dying and he leaves the battlefield to go to her. It's similar to the God Of War novel with Levi in.  Anyone able to help with the title?