I'm the Mysterious Leader of the Salvation Organization - Chapter 583:

A 13-year-old deaf teenager living in the 21st century suddenly found himself as a young boy in Japan during the early 1900s. With two World Wars, two nuclear bombs, Hitler and many other disasters awaiting his future, he thought things couldn't get worse.Except it did.He found out later on that he had actually reincarnated into the world of Demon Slayer where man-eating demons ruled the night. He thought things couldn't get worse.Except it did.But hey! At least he had unparalleled talent, incredibly special eyes and future knowledge.How will the story of Demon Slayer change with the addition of this unique character? Will so many still die if the Hashiras had one more pillar in the final battle?Or will the story end on a much happier note?

The best way to declare war on a spy as an ordinary person is to become a spy as well.As a spy, if you want to go to war with a powerful espionage organization, join an equally powerful espionage organization.If you are unable to join any powerful espionage organization, then establish your own espionage organization and fight until destruction or victory.This is the war of spies, telling the story of how a group of ordinary people achieved extraordinary success.

“There are no heroes. In life, the monsters win.”

...

In 2106, [Mayhem Online], a fully immersive VRMMO game, was released. Soon, it dominated the world's economy when people could exchange the in-game currency with real-life currency and vice versa.

In the year 2107, Flynn Grey, a 22-year-old college dropout with an ambiguous history, joined in the fray of billions of people that had already started playing [Mayhem]. Hoping to uncover the game's secret and earn a fortune, he spent months on adventures without fruitful results.

For better or worse, Shura, Flynn's in-game character, ends up in a great Wyvern's den, acquiring a hidden class and a monstrous race. Join him as he defeats his past and paves his way into becoming a true legend in both worlds.

On her wedding day, she was humiliated; her status as the legitimate wife was instantly changed into that of a concubine.

“wh***! Marrying you is my life’s shame!” These were the hurtful words that came from her childhood sweetheart, now husband.

….

Jiejie, jiejie, thank you for your sacrifice. Jiejie, if you’re kind then go. Meimei will replace you and take good care of your husband, to help you enjoy the blessings that you are unable to enjoy!” these words spat out by her smiling cousin made her whole body feel cold.

….

“You are shameless! There is no need to say anything! From now on, our Shen family will not have you as our daughter! Someone! Throw out this shameless woman!” These were her relatives?

…

Becoming the target of criticisms, and being submerged in a small lake, she realized that all of this was the result of another person’s scheme – but it was already too late!

…

Instead of dying, she went back to the past, back to where both feelings were still alive and were loving towards each other; back to when she was not yet an orphan but the doted on Di daughter of the Shen family.

No matter what, in this life, she would never allow anyone to hurt the people she loved. And those people who harmed her in the previous life, she would make them pay the price!

- Description from Novelupdates