Strongest Counterattack - Chapter 305 - Completely Alive

At 3 years of age, her father went missing. At 15, the muscle in her hand snapped. At 16, her mother passed away in a car accident. At 19, she was framed by her uncle. At 22, she was burned alive by her newly- wedded husband and her best friend. Perhaps it was God’s sympathy that allowed her to return to the time when she was 15 years old to re-live once more. The previous lifetime of being low- key and having forbearance resulted in betrayal and misery. In this lifetime, she must be lofty and domineering to let those who have bullied her suffer a terrible end!

- Description from Novelupdates

It was a dangerous era. Extraterritorial ferocious beasts occupied 90% of the living space in the world, while humans could only survive in a small space. Fortunately, some of the surviving humans awakened to genetic martial arts! Breaking the shackles of one’s genetics was the foundation of cultivating martial arts. Lin Feng, who was born with congenital disease, could not experience a breakthrough. However, by some fateful encounter, he awakened to the ability to merge genes.

Jang Joonbum started stream to enjoy an easy life.

For unknown reasons, he finds himself transported to a parallel world's Japan, unexpectedly taking over the body of a soon-to-be high school student who had died accidentally. Surprisingly, he did not inherit any memories. However, the first challenge he faces upon arriving here is a language barrier...Just as he struggles to communicate with his new family, a heavenly voice arrives: the black technology system has been activated, and the initial item—translation konjac—has been distributed.This is the story of someone with above-average intelligence but almost no physical strength in the Classroom of the Supreme Power.