The Lordly Grim Reaper

A prideful grim reaper was sent to earth for his next mission to write the name of a mortal being in the Death Note. What will happen when he fails to pen down the name multiple times?
...
"You've never had mercy on anyone before taking their life?"
"Why would I have? I'm a Grim Reaper and that's my job."
...
"You miss your parents. Don't you want to be with them?", the half-face which was now visible to Ellen appeared holding a tranquil gaze at the latter.

"Don't be ridiculous. I told you they're dead", although the music was playing in her ears but it was a soothing melody, mild to have sounds from the other world to come across.

"If there were a possibility, would you leave things here just to be with them there?", grim asked eyes looking anywhere but at the ordinary mortal who was left at the mercy of him. Indeed, it was the agony of time to be left at the mercy of someone who doesn't know the meaning of the word itself.

"No. I want to live."
...
Shawn, arrogant, full of himself Grim Reaper.
Ellen, a writer on Webnovel living with a dream to be successful one day.

What will happen when an immortal being shows emotions for an ordinary mortal?