The Insignifcant Female Supporting Character Actually Became a Bigshot in the Novel! - Chapter 134 - : Free Bill

Lucien, a guy who has nothing but the desire to save his mother. To get strong enough, he makes a contract with the demon of L.u.s.t. And now, only by making a great harem, will he gain the power to protect those dear to him.

The notorious imperial court lackey and the meritorious military general were well-known for their mutual dislike, a pair of arch-enemies set in stone. Who could have foreseen the unexpected change in the winds of heaven: the general injured on the battlefield, both legs disabled, and even forced by the emperor to marry his nemesis.  

With one marriage edict, two people with mutual hostility are forced to marry and live under the same roof. Yet after these long days together, they come to the realization that this fellow is not truly devoid of any saving grace/unattainable and high out of reach.

- Description from Novelupdates

Shortly after his marriage, Lin Jiage was thrown out of his house.

Arnold never thought his gaming skills would land him in a romance novel—as a doomed side character, no less. To survive, he hijacks the heroine's “system,” bending the story to his will. But when he dodges a deadly duel, he catches the eye of the heroine, Lara, his own step sister—and her love is a dangerous game. Arnold must outwit the plot and his step sister who's not afraid to kill for love. In this LitRPG romance gone wrong, survival isn't just about beating the system—it's about escaping the heart of a yandere.