Superstar From Age 0 - Chapter 641:

This is the story of a boy who lived a secluded life in the mountains, tending his farm, rearing his fish, and dreaming his dreams. Eh? Did I suddenly conquer all worlds and become the big boss? Or am I still in a dream?

- Description from Novelupdates

Nero was an orphan boy who one day went to sleep like any other day in his apartment. However, what he did not know that the moment he slept, it would be his last day of life...Or at least that was how it should be.Nero's soul wandered between the worlds and ended up entering the body of a girl who was trapped in a human mutation laboratory. While the girl's soul was still alive, he hibernated inside her body.After so many tortures, the girl named “Zero” in the laboratory died. But, it didn't end there, when the girl died, something very strange happened, something took control of the girl's body and that same thing escaped the laboratory.It was when Nero what that was hibernating in the girl's body woke up and realized was completely naked. In addition, he realized that he turned her into a beautiful winged woman with white hair and some pink strands.

She, a renowned assassin of the 21st century, actually crossed over to become Su Manor’s most useless good-for-nothing Fourth Miss.

Rein Aster was just a herbalist farmer from a border village.A nobody. A background NPC in a story filled with prophecy and divine warfare.But by chance—or fate—he saves one of the 7 Demon Lords during a catastrophic war event. Instead of killing him, she falls for him.Obsessively. Violently. Eternally.And then… so do the others.Each Demon Lord tries to trap Rein as her personal lover/pet/priest/husband/god, building dungeons, illusion palaces, soul prisons—but Rein keeps escaping. Quietly. Cleverly. Never fully rejecting them—but never submitting, either.Why?Because Rein realizes something:The gods are worse than demons.The heroes are tyrants in shining armor.The world is collapsing—and he’s the only one they all listen to.So he hatches a plan:Use the Demon Lords’ love to take over the world.Pit them against the heroes. Unleash them on the gods. Make them fight for him. Make them kill for him. Then tame them all.Not as a king.Not as a savior.But as the lover they would burn the world for.__________The yanderes here are darker than what you might be used to.You have been warnedThe entire novel has a dark feel. Atleast read the first two minor arcs