Toaru Majutsu no Index - Volume 15, Chapter 4: The Paper-Thin Difference between Self Derision and Pride. Enemy_Level5.

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.

I’m Kuna, a former countess’s daughter, working at the café of the Adventurers’ Guild “Shield of the Silver Wolf.” Together with my Carbuncle, Lulu, I spend my days serving customers with special drinks infused with healing power!One day, a customer from my own White Wolf tribe visits…With the newly joined companions, I find myself facing my family, who is trying to take me back to the Kingdom of Aluda!The happiness everyone in the guild has given me—I will protect it this time!This is a life-reversal story filled with fluffiness and healing power!

Su Yao passed through and traveled to the Marvel world to become a mutant. He was still in the experimental base. He expressed a little panic…

Fortunately, at the critical moment, the mutant ability ‘imitation’ was awakened to imitate the opponent’s ability!
…
Imitation object→Orochi (title: Sun God, Will of the Earth)
Imitation object→Wanda (title: Scarlet Witch, owner of chaos magic)
Imitation object → Sun God…
…
Professor X: “We must find him as soon as possible and guide him to control his power to avoid causing irreparable disasters!”
Magneto: “You are my child???”
Thor: “Brother?”
Loki: “?”

- Description from novelbuddy

Luo Yi, a high school dropout in his original world, was isekai’d into the world of the Witcher 3. Starting out as a weak boy named Roy in the village of Kaer, Lower Posada, he was determined to grow stronger, no matter what it took. The first step toward becoming a legend was to kill. And his first kill was… a rooster. ‘You gain 1 EXP.’ Of course, Roy had his own cheat system like all the other isekai protagonists. His first step to becoming a legend started now…