MTL - I Try To Become An Immortal Through Mortal Science - Chapter 16 see the picture

Su Yu was in a third rate university when the “Sky Holes” appeared, his school fell through the “Sky Hole” and appeared in the middle of a forest that was teeming with terrifying creatures.

This legend tells the tale of the protagonist, Kuroki summoned to protect the demon king from the hero.

Kuroki, unbeknownst to him, suddenly came to another world. He was summoned by the demon king, Modes. The territory which the demon king overrules was in the midst of being destroyed because of the hero. He had no choice but to bow before Kuroki.

“Please save us, Savior Dono!”

Kuroki nodded, deciding to save the demon king due to an unexpected turn of event.

During this revolution era book, Fang Ru was the original heroine of the cannon fodder. She died in repression and infamy under the deliberate calculations of the transmigrated heroine.

After being reborn, Fang Ru decided to stay away from the leading male character and start over. However, without Fang Ru’s involvement…

The leading male character became crippled and turned evil. He suffered mutual torment, mistreatment and hatred with the new female protagonist, who also lost her chance at love and career.

The lovelorn supporting male character was forced to live like a widower for the rest of his life after being manipulated into marriage by someone with a rich family background, even still he harbored feelings for someone else’s wife.

- Description from Novelupdates