Princess Fischl - Chapter 66 - 65. Schism.

16 years old-- most boys would be falling in love, as their hormones all rise to unprecedented levels. Most boys at Riley's age would have dreams; dreams that will slowly grow into passion. Riley, however, at age 16... killed the world's number 1 superhero.

Eira Kingston, a feared assassin, never imagined that death would lead her to transmigrate into the body of Ephyra Allen, the disgraced first daughter of the once-powerful Allen family. But what shocked her even more was the soft mechanical voice in her mind, addressing her as “master” and informing her that her soul had returned to its original body.Eira dismissed the strange voice, thinking she was having a post-death hallucination. But waking up in a hospital, with memories that weren’t hers flooding back, she was forced to confront the truth.Ephyra’s life had been nothing short of a nightmare. Despite being the legitimate daughter, she was labeled a bastard, shunned by all, and overshadowed by her scheming stepsister, who had stolen the love of her father and her betrothed. To make matters worse, the wealth and status the Allen family enjoyed were all thanks to Ephyra’s late mother, and the only reason she hadn’t been discarded entirely was due to her mother’s inheritance, locked away until she turned eighteen.But Eira wasn’t one to be defeated by circumstances. If she was going to live Ephyra’s life, she would do so on her own terms. She would destroy those who had caused Ephyra pain, claim the inheritance that was rightfully hers, and find out who was behind her own death. Because if there was one thing Eira knew how to do well, it was to survive—and make her enemies pay.However, being a high-schooler with nothing to her name wasn’t enough. As Ephyra, she’s powerless, but as an assassin, she’s lethal. Still, even that wasn't enough until she became the contracted wife of Lyle Aelion—a powerful, enigmatic figure in the business world with a secret illness. And it turns out, the only thing that can relieve him is her scent.

The leaves of the chess game beside Lanke, and there is no one playing chess among the old trees
Xing caused Tian Yuan’s first son, and then looked back at the vast mountains and seas
When he woke up, Ji Yuan became a half-blind beggar in a dilapidated mountain temple.
A real person has a sword and a magic stick has a mouth, which is the foundation for Ji Yuan to settle down in this terrifying world.

- Description from novelbuddy

Demon Lord! A symbol of terror and evil! Killing and death are associated with him! In a magic country, a being was summoned. This being was the most demon lord unlike of all demon lords in history.

“Your majesty demon lord, please sign a document here. But please be careful not to put your hand at the wrong place.”

“Your majesty Ya Lin, human army are invading us but I will protect you with my life!”

“Hate you! Don’t come closer! You are a real pervert demon! I hate such demon the most!”

O God, what is this? I just wish to be an ordinary person with carefree life and stuffed with food till death. Why I am the one who will become the future husband of the demon princess, the future demon lord? And also completing a near impossible task ——-resurrecting my mother-in-law? Luckily becoming a demon does have its own benefits, granting each demon ability to cultivate skills.

However, what type of circumstances are this, mission going to other worlds and conquer them?

- Description from Novelupdates