My Reborn, Sweet Little Brother Has Gone Psycho! Run!

[Reborn + yandere and unhinged + mutual salvation + both leads are strong. When he's gentle, Jun Jiuci is sweet and obedient, calling her "Big Sis"; he's incredibly sweet. When he's angry, he's a devil who'll drag Bai Shang to hell with him. A little angst makes the sweetness even sweeter]

Bai Shang is reborn, her old ailment cured, and just as she's planning to make up for the regrets of her previous life, the child she raised pounces on her. She's also bound to a baffling System, and is completely at a loss.

"Bai Shang!"

The man's crimson phoenix eyes glisten. His voice is husky as he whispers in Bai Shang's ear, his thin lips curling into a smile, menace mingling with tenderness.

"This time, why don't we just leave together? I've picked out a few coffins. Which one do you like?

That way, you won't run off anymore, right?"

Bai Shang: I'm really scared. Where did my little brother go?

How did the sweet, adorable little beauty suddenly turn into this? In her previous life, hadn't she even helped him save several people? Why was he showing her no mercy at all?

Later, Bai Shang realizes the price of being reborn is so steep.

"A-Shang, a lifetime without you is too long for me. This time, it's your turn to beg me."

Jun Jiuci smiles, gentle and cruel.

If the heavens hurt you, I'll defy them for your sake. If everyone abandons and betrays you, I'll be your eternal believer.