Isekai Maou to Shoukan Shoujo no Dorei Majutsu - Volume 1 Chapter 1.12

In 2040, The Earth was bathed in powerful radiation when a star went supernova, this radiation granted 50% of humans superhuman abilities but also created a nightmare for them as animals, insects, and carnivorous plants were mutated and became overpowered with intelligence, human started teetering on the brink of survival, a boy with no powers and no father, with a mother in a coma, seems destined for obscurity, but one night changed his life, with a new found hope to cure his mum from the everlasting sleep—Gene Elixir— he went on on a journey that would reshape his destiny...~Voracious Sovereign... Gene Devourer...Pray you won't be devoured by this power you wield which hunger is insatiable~~You call yourself an opportunist... But... you aren't free. A hungry man is not a free man...~

Ji Huan’s parents both died in a traffic accident.
Unexpectedly, his older sister also meets the same fate.
Yet everything starts when he says “goodbye” for the last time.

Hunting monsters? Genetic comparison?
Ji Huan flees with his older sister’s posthumous child to his hometown, Bade Town.
The three Grandpa, grandson, and nephew all live interdependent days.
However, inside the swaddling clothes is not a human baby,
But a monster…

Black egg body, white ring eyes, red mouth.
A child, ah! Doesn’t he have two eyes and a mouth! Resembling an egg, he is Ji Huan’s cute nephew!

Vermilion tiled wall, white lotus pond, convalescent courtyard.
This entirely neatly handsome and elegant young man: Ah Jin.
However, he told Ji Huan about the secrets of the monsters and discreetly taught him.
Bade Town is also slowly being covered in monsters…

Or, the record of a small countryside monster’s growth.

- Description from Novelupdates

Regaining the memories of his previous life, Cyril realised that he was an otome game’s character, the villainous daughter– Sophia’s butler.At the rate things were going, Sophia would eventually have the prince stolen away from her by the heroine, fall into darkness, and be executed.Wanting to save the villainous daughter he was so fond of, Cyril moved to eliminate all the factors that would cause her to fall into darkness, raising her up to be a talented and beautiful girl who could win the prince’s love, however…

Ask, under the starry sky there was a beauty, her black hair like eternal night, bright eyes sparkling like stars, her powerful magic made the world tremble, her supreme beauty made all creatures submit, who was this beauty? “That’s right, it’s me, the Witch King, Dorothy!” ‍