Bog Standard Isekai - Chapter 1Book 3:

During a luxurious cruise trip, he and she met unexpectedly~ Two months later, she was pregnant. They got married because of the child, but on their wedding day, he forced her to sign a divorce agreement. After the divorce, she thought they would have nothing to do with each other anymore. Who knew he would appear in her life again. When she went on a blind date, he showed up: “This is my ex-wife. She just separated from me.” When she went traveling, he followed her. She was furious: “We are already divorced, what do you want?!” “Let's get back together.” He started to pester her shamelessly. Given all the misunderstandings between them, how should she decide? Let's see who surrenders first~

Our straight (?) bottom woke up ten years into the future and found himself on the bed of his childhood friend… At the start, the bottom was shocked to his very bones, but he soon quickly accepted this premise and found the whole situation to be rather amusing. Precisely then, the bottom once again went back to his timeline — back to when he and the top were just platonic childhood friends.

Jiang Chen had unexpectedly found himself thrust into a world of cultivation, stepping into the role of a core disciple within a famed sect. Fated to be the villain, his future loomed with calamity. He had plotted against the protagonist, crippling his dantian and leaving him a disgraced outcast teetering on the edge of expulsion. Were it not for an unexpected twist, Jiang Chen’s part might have ended as a mere footnote in the protagonist’s glorious tale. Fully aware of his precarious position, Jiang Chen’s lips curled into a sly grin. Alone, he mused: ’Is the protagonist powerful? Without a doubt.’ ’But will I tremble in fear? Absolutely not.’ ’Why? Because I have the Immortal Great Villain System!’ ’Wait... there’s more than one protagonist?’ ’Well, isn’t that just perfect?’ With a determined glint in his eyes, Jiang Chen declared to himself, ’As the ultimate Great Villain, I will defy the will of Heaven and seize my place at the summit!’

“Jiang Yu transmigrates into a novel and becomes a side character in the book.