Steel, Guns, and the Industrial Party in Another World - Chapter 279:

Born into the Thornhill family, Eliana should have been dealing with succession planning and heiress training. But instead, she’s dealing with the crocodile tears of her cousin Alexa.As if stealing her Fiancé wasn’t enough, she’s out to pin everything onto Eliana.Trust issues - Eliana.Popularity issues - Eliana.Landslide - Must be Eliana.In an attempt to end her cousin’s jealousy-ridden machinations, Eliana is forced into a relationship with a childhood disaster, Lucian Alder Sinclair, her most tempting nightmare.Lucian Sinclair has always been synonymous with perfection, at least to most people. But to his family, finding someone who could handle his aloofness has been the top priority.Forced to return to his home country at the behest of his grandfather, Lucian fortunately encounters Eliana who’s in need of a ready-made partner.Constantly up at each other's throats, then into each other’s arms, may the lies they’ve told hold up against discerning family members and unrelenting pursuers.

Stealing Heroine from Protagonist with SystemWARNING MATURE CONTENT!!!!!R-18

The worst student of Westroad Academy. The disgrace of the Blake House. A new soul enters the body of Frey Blake, who couldn’t overcome his miserable life and chose death instead. “What’s with this body? I’ll have to work on tuning it from scratch.” The Great Mage Lucas Traumen, with the body of Frey Blake, gains a chance at revenge!