This Omega is Immune to All Abilities - Chapter 20

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.

Chu Yang, the Ninth Master of the Nine Tribulations Sword, sacrificed almost everything he had for the sake of improving his martial arts, including the love of his life. After spending three years locating the fifth fragment of the Nine Tribulations Sword, he was ambushed by all sides at that very place. Mortally injured with no means of escape, Chu Yang executed a sacrificial technique by plunging the Nine Tribulations Sword into his very own heart. “With the blood of my heart, ten thousand tribulations will collapse!”

After witnessing the death of all his ambushers, Chu Yang’s vision began to darken. At a distance, moments before his death, he saw the mastermind who had plotted his downfall — Mo Tian Ji. With that, his eyes finally closed.

However, with a start, Chu Yang once again awoke to find that he had returned to when he was sixteen years of age! Furthermore, the Sword Spirit of the Nine Tribulations Sword now resided within his Dantian, the energy center of his body! From that very moment, Chu Yang would then begin to right all of his past regrets, and carve his very own legend by fulfilling his destiny as the final Master of the Nine Tribulations Sword, and defeating the Heavenly Devils beyond the realm of the Nine Heavens Continent.

- Description from novelupdates

Anger. Pain. Desolation.

However, he did not know that he was not raising just a harmless pet, but a biological weapon secretly made by the government… a real monster.

As a former librarian, Rand felt that he had been living an ordinary life, the one that he had reclaimed unconsciously every single day.

Recently, he has been a little upset because the pet fish he accidently brought home to raised seems to have undergo some strange changes

Well, it turned into a merman.

- Description from Novelupdates