Isekai Maou to Shoukan Shoujo Dorei Majutsu - Volume 10 Chapter 4 part3

Gu Jin crossed into a novel as the supporting character and best friend of the main female lead, Cheng Xin.

Cheng Xin was frequently surrounded by men of status and quality. As Gu Jin was the female lead’s dearest friend, she doesn’t mind settling for the leftover meager soup if the female lead chose to eat the meat. The two sisters believed they’d enjoy this friendship for a lifetime.

But just as she was ready to latch firmly unto Cheng Xin’s golden thigh, she discovered the body she crossed into had memories of future events beyond the novel’s plot, finding out that her marriage would end in utter failure.

The female lead, Cheng Xin who often quarrelled with the male protagonist would head over to Shao Chong for comfort even though Shao Chong was married to Gu Jin. And after several incidences, Gu Jin advised Shao Chong to have a sense of propriety as her spouse but he told her not to think too much about it, claiming that he only maintained a pure friendship with Cheng Xin.

On the day Gu Jin was kidnapped, her good husband stayed by her cousin’s side and accompanied her to the hospital.

When Gu Jin transmigrated into this new world and learned of the truth, she did not wish to waste this new life as a supporting role for her cousin as the previous soul had done. She’d not live a life as a spectator in someone else’s love story. No. She would be the protagonist of her own romance in this new life.

- Description from Novelupdates

When Simon dies, it turns out there's more to combat than lightning reflexes with his controller, and the path to becoming a hero is more brutal than he can imagine as he descends into The Pit. Death after Death is a dark, time loop/Isesaki story with roguelike elements, that explores some of the common tropes in a different light.

A world where the [Demon King] was defeated by a [Hero] that came from another world. People carelessly forgot about their fear of the [Demon King] and of monsters, living in peace.

In a forgotten and run-down cave in the mountains, a new monster that should not have been born was given birth.

The monster’s name was the [Black Ooze]. It was nothing exceptional other than its black color, an ordinary slime.

However, this slime had the special characteristic of being able to take the abilities of the living things it swallowed. It preyed on an insect that had paralytic poison, as well as other animals. Following that, it attacked a human, obtaining his knowledge and [Desire].

Before long, the monster established its target as the female mage that came to explore the cave.

This world still wasn’t aware.

With one touch of the stone, Tyron receives his Class and his life changes forever.In an instant his bright and promising future as the scion of two powerful Slayers is torn apart and he must make a decision.Will he allow his Class to be purged from his soul, or will he cling to it, abandon all that he knows, and rise to power?