Super Watch: Life Killing Doctor

*For some people he was a ridiculous doctor. Everyone had given him the nickname of Death! 
In the past six months, Even though more than ten patients had lost their life by his hands. 
Still there were many influential people were scrambling for him… 
… 
As for himself, he always tell himself everyday. 
“Strictly speaking, I was not a qualified doctor. I just transferring a person's lifespan to another person.”
Why could he be able to do that?
Well, that because He had a magical watch which could save and kill anyone, No matter what illness they have. 
Then why there were still some people die on his operating table？
Well, That is because the hell does not always take the bad people’s life in time, but he will! 
… 
Where did he got this watch? What is his story?"