Isekai Maou to Shoukan Shoujo no Dorei Majutsu - Volume 8 Chapter 3

Mira is determined to be a botanist—no matter how dangerous or violent it may become. Mira made two requests upon entering the multiverse: a botany class to further her research and to be dropped off in an isolated forest far from the violent god-rearing system BS going on. She was granted both—but not in the way she expected. The system abandoned her in a hellishly dangerous forest—where she earned a rare class that excelled at killing things.

At her cousin's birthday party, she was schemed to have a relationship with her cousin's fiancé, becoming the most shameless woman among rich families, and therefore married to that man, the most influential big shot in the city.After marriage, the wholehearted love only brings endless humiliation and disgust.Later, her cousin returned. He threw out the divorce agreement, saying, “Give Mrs. Leng's position back to her.” He even took their child and gave it to her cousion who was unable to bear children.She finally became disheartened and fled far away with their child, completely disappearing from his world.On his wedding day, he suddenly learned the truth and realized that his white moonlight had always been her, not her cousin.“If love is an isolated island, I'm willing to settle there for you forever.”

“Obtaining the topmost degree of talent in sword arts in the world requires giving up 72 years of lifespan, which leaves you with only five more years of your life. At the same time, you will never be able to feel love, kinship, and friendship, and you’ll end up leading a lonely life until your death, unable to procreate, or to have any descendants.

“From now onwards, everything related to happiness in the human world shall no longer be of your concern. Are you willing to accept this?”

“Hahahaha, I’m already alone bereft of all support, my hopes dashed to pieces, shouldering only absolutely irreconcilable grudge and hatred, why would I disagree? Why would I not want it? I couldn’t ask for anything better!!”

His sword sweeps across the Divine Continent for seven days and nights, moving 90,000 miles through the starry skies, unhindered.

He slays saints and buddhas in Heaven, slaughters demons and devils in Hell, sweeping away all the grievances in his heart.

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- Description from Novelupdates