Reborn: The Duke's Obsession - Chapter 43 - Forty Three

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

Enigmatic hands, spectral frame, and one cunning strike just like the swing of the Grim Reaper. The Supreme Assassin takes on the mystical world, and how his legendary tales sets off, progressively ascending the altar to becoming the best.

- Description from Novelupdates

Lucille was a top student when she suddenly passed away due to a car accident she was transmigrated to the novel that she was reading before her tragic ends, and what's worse she was transmigrated in the body of the Villainess Acantha Solaris who will also die without receiving any love from everyone.

“I, an Immortal Cultivator in this world of superheroes, alone understand the Dao.”Elius Northrim had a peaceful life—until he blacked out and awakened with tragic memories of his past life.Along with those memories was a realization that in his eighteen years, he was living in a brutal superhero universe, and his ruthless alien father—whom he had never met and a SUPERMAN equivalent of this world—was coming for his life because one of his brothers, the main character of the comic awakened his Solarion bloodline.Surviving while being mistaken for an awakened Solarion offspring of his father too, Elius must keep the truth hidden—he’s not one of them, but an immortal cultivator.If his father discovers the deception, both he and his mother will die.But the worst part is that he has become his father's favorite among the two. To avoid being constantly under his father's watch, Elius enrolls in a superhero academy, blending in while secretly growing stronger.However, with rival students, watchful instructors, and his father’s looming presence, one mistake could mean death.Now, he must master his powers, play his role, and survive—before his secret is exposed as a lone immortal cultivator in this world of Superheroes.

The boy who Sneaks in My Bedroom Window