The supporting character's harem is very normal - Chapter 344 Freedom for Rolen

A supreme expert in the Immortal World had died, and a strand of his soul returned to its original body on Earth. Tang Xiu discovered with amazement that ten thousand years passed in the Immortal World, yet only a single year passed on Earth.

Ruthlessly betrayed by his lover and trusted friends, Tang Xiu found that his soul went back to his previous body on Earth, and, despite he spent 10,000 years in the Immortal World, just a year has passed on Earth and many things have changed. Having an unsurpassed knowledge, Tang Xiu will protect his loved ones and go back to the Immortal World to take his revenge.

- Description from Novelupdates

Shu Yu has passed through the book, and has become a poor cannon fodder who was implicated by the dead female supporting role and only appeared twice and was finally exiled for thousands of miles.

After finding that he could not change the result, Shu Yu decided to eat, drink, lie down and wait.

Who knew that the exile had not yet come, but she was suddenly told that she was not the daughter of the Shu family.

Her biological parents were peasant households who lived so hard to make ends meet that their house was leaking.

And the Shu family decided to obliterate her in order to hide her blemish.

Shu Yu: Come on, I can’t kill you.

Returning to his biological parents, Shu Yu finally sighed as he looked at the plate of pickles and a bowl of porridge on the table and placed in front of him, as well as his parents’ nervous and bewildered expressions.

You can’t lie flat, or you’ll starve to death.

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], a Wuxia novel I’ve enjoyed reading.After meeting the rescue team of the ‘Three Great Doctors’, I found out that one of the person I saved was the protagonist of this novel, the future Demon King ‘Yeo Haryun’!“Hey, since I’m indebted to you for saving me, call me ‘hyung’.”For saving his life, I become sworn brothers with the future Demon King, and the White Dragon Godly Doctor, one of the most knowledgeable people around, recognized my potential and took me in as his disciple. This is the story of how I became the greatest physician in Gangho!