Doctor’s Rebirth

" I had been abroad to do medical volunteer work, when I was swept up in a civil war. I was killed by a rebel soldier while taking a bullet for a patient. But when I finally woke up, I had become a child?!?And in front of me stood a destroyed carriage and a group of oddly dressed people, who were unconscious!\"It's just like a Murim world.\"As I hurry to perform first aid in an attempt to save even one person, I realize that this world is that of [The Supreme Demon King