Psycho villain I Raised Wants to Marry Me

Transmigrating into a novel as a ruthless villainess—just to fight over a man with the heroine? Yeah, no thanks. Clarissa knew money was far more reliable than men. Then she discovered that the terrifying villain everyone feared was actually the sickly, pitiful boy next door. He was all skin and bones, hardly looking like someone destined to bring chaos. A few moments of soft-heartedness led her down an unexpected path—raising this little villain herself. Years passed. The weak, clingy kid grew up into a tall, handsome young man—charming, intelligent, the pride of his professors and the idol of his peers. Just when Clarissa thought she had successfully "reformed" him, reality hit her like a slap to the face. On his eighteenth birthday, she casually asked, "What do you want as a gift?" He fixed his dark, burning gaze on her and said, "You."  The boy she had raised suddenly pinned her down. "I want you to be my woman." Clarissa ran. He caught her. His voice was low, desperate, dangerous—"Don’t run, sister…"  "If you abandon me, I’ll go straight to hell." It’s not smut or some twisted step sibling seduction/romance.  It heads in the darker romance direction eventually, but my work doesn’t really have depressing or dark vibe.  I want it to be a more light novel or revenge fantasy novel, and it is a story of mutual redemption.