Citadel for All: The Only Unit Angel at the Start of the Game - Chapter 539

A mysterious natural phenomenon caused the Earth to be plunged into darkness. The world turned into an endless bloody chaos and mankind is on the brink of extinction…

Chu Yun Sheng, an ordinary white-collar worker, discovered his family heirloom book shining a bizarre light by accident. Out of curiosity, he tried to study the heirloom book.

After a long research, he still only understood a few symbols written in the ancient book. However, he was shocked when he figured out what messages the ancient book tried to tell him: the sun will disappear, and humanity is doomed…

He tried to spread the message, but no one believed him; his family and friends even tried to take him to see the psychiatrist. Eventually, he gave up telling anyone, but prepared for the apocalypse in secret.

Until one day– the sun really disappeared…

- Description from Novelupdates

Others treated disease to save person, he treated disease to steal heart.

The Frost Goddess was deeply captivated by him. The gentle and kind beautiful teacher was completely enchanted by him. Even the cold and beautiful female assassin melted quietly because of him.

Competing in medical skills? He was the one who treated the Godly Doctor. Competing with backgrounds? Leaders rushed to him. What? You actually wanted to compete with him in a match for match? Looking at the gentle girl beside him, Tang Yu had a headache as he said, “Beautiful girl, how did you fall in love with me?”

- Description from Novelupdates

After her parents had both died in an accident, she had to sign an agreement with him to save her family's company.

It was stated in the agreement that he would save her company on the condition that she would allow him to do whatever he wanted with her.

Just because she resembled the woman he had once loved, he had toyed with her a million times and tortured her in every possible way.

He humiliated her in front of others and then abandoned her. She had loved him, but had suffered.

It wasn't until the agreement expires that she finally ran away from him. By the time she left, she was already pregnant.

A few years later, she brought her adorable child back and became strong and cold-blooded. When they met again, he doted on her so much …

On a certain day, a certain thought came to Japan’s Sun Goddess. ——Aren’t there too many Japanese people being abducted to other worlds? It’s true that the large majority of Japanese are diligent and docile and soft-hearted, which makes them pretty much the best people to ask for favors. “But recently it’s just gotten way too out of hand…… Oh, I’ve got it! Whenever a Japanese person is summoned, I just have to summon an otherworlder!” And now, every time a Japanese person is summoned, princesses and elves and beastmen and whatnot are reverse-summoned. Under the acknowledgement of the government, they begin living in Japan. Today, too, Japan is at peace. And so begins this laidback isekai cultural exchange story♪