Isekai Kaeri no Ossan wa, Fusei Sukiru de Fathercon Musume-tachi o Tororori ni - Chapter 5 – To Come Round

After putting a suggestion to add a mercenary in a bad Murim novel he read, Leo would finish a mission with his NPCs before sleeping. Or so he planned. For some reason, he was transported into the said novel as the extra mercenary added by the author. His loyal NPCs, a yandere secretary, a happy-go-lucky assassin, a sexy puppeteer, and two weapon maniac guys start to become sentient. He lead his mercenary band ’Hallowed Insects’ toward an an unprecedented future in a Murim most turbulent era while enjoying his time. Fortunately, they still have their futuristic equipment with them. Tang Clan have a Poison Dagger, they have a Photon Sword. Shaolin Sect has a Qi Blast, they have a Railgun. And of course... “How much are you willing to pay to employ us? By the way, Demon Sect pay us 50,000 Golds to join their side in the upcoming war.” ... he always sided with the highest bidder.

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

Shao Xuan joins a friend in his expedition to a recently discovered archaeological cave. After he picks up an ordinary looking stone he is teleported to a different world and wakes up in the body of a small orphan child. The world he is in now is still in its stone age with primitive tools made of stone and the ways of the people are savage. Savage isn’t the only thing special about the people though, because they have superhuman strength, jump higher than trees and punch stones. In short, they are able to cultivate their bodies. Despite all this, it is a real struggle to survive because of the scarcity of food. Together with Caesar, his pet wolf, he tries to survive in this cruel world.

After 20 years of dedicating his life to opera ever since he had quit the performing arts high school, he had failed at an interview. Losing his motivations, Jo Yunjae depended on alcohol to live out his days until one day, he had been sent back 20 years in time, to the day before his high school admission.