Winter Swan - Chapter 148:

This is a story about the protagonist getting the system, going crazy in the biochemical apocalypse, producing aircraft and tanks, destroying zombies, saving good people and killing bad people.

- Description from novelbuddy

“….Krische-sama, are you not afraid of killing people?”

“……? No. After all, it doesn’t hurt Krische.”

Although gifted with the talent to do anything with ease, the girl lacked empathy.

In her world, there is only loss and profit. No goodwill, no love.

Inhumanly recognizing cold, mathematical logic as everything, she looks at everything in the world through calculating lens.

Return given profit with profit, loss with loss.

The girl was undoubtedly pure, yet undeniably abnormal—

Her favorite things are cooking, food, and being pampered.

Her specialty is mu*der.

—- This is the story of a slightly unhinged girl being surrounded by kind and loving people, and her journey to find happiness.

Waking up, Kim Hajin finds himself in a familiar world but an unfamiliar body.

She is the slow-witted idiot of the Prime Minister’s Residence. Everyone bullies her. He is the most respected and unfeeling Prince, with frightening ability and absolute envy! Together, they are conferred an imperial edict of marriage.

She acts stupid and tries to decline in every way possible while he despotically escorts her into the wedding…… everyone ridicules the match, but no one knows that the “idiot” has transformed from a loser into a talent.

After the marriage, when they encounter the Empress Dowager examining the room, they act in concert with each other and pretend to be two mandarin ducks deeply in love. Afterwards, she laughs, “The performance has ended. Your highness, please return.”

He laughs softly, “Since you’ve got onto this Prince’s bed, don’t even think of getting off.”

- Description from Novelupdates