Shini Yasui Kōshaku Reijō to Nana-ri no Kikōshi - Chapter 107 - Duel Trial (part one)

She, a modern hidden ghost leader of an organization which gathered insane prodigies proficient in the various differing skill-sets. Highly skilled in medicine and poison, executes covert assassinations, viewed as insane and demonic in the eyes of people of the world. Killed in an accident, and reborn into the body of a disfigured young girl.

What? Face disfigured, identity stolen? A return to the family dim and hopeless? Her identity can be given up, her family can be forgone, but as for the one who harmed her predecessor who inhabited this same body, if she didn’t at least make them scream in unimaginable agony and throw them into a state of wretchedness, how could she live up to her demonic reputation? Endless turmoil ensues and it’s a battle to dominate over all! See how she shook the world dressed in a suit of red, her sword up against the dominant powers that rocked the Heavens! Her name spread across the seas, shocking the earth!

- Description from Novelupdates

"Your bed is cold," spoke a voice in the room that had her eyes go wide in fear. Nervously, she turned around, gulping softly to see a shadow on her bed as if someone laid down there. The man who had been lying down sat up emerging out from the shadows where he had been waiting for her.

Travel to the world of pirates and become Belmer’s adopted son! Nami and Nokigo’s older brother! Liu Ye, has been planting oranges for five years!

One day, Liu Ye, who suddenly realized that he couldn’t go on like this, with the mentality of trying, meditated in his heart: “System?”

“I’m here.” A cute voice like classmate Xiao Ai rang.

Awaken the strongest clone system! Every time you level up, you can get a clone!

Absolute loyalty, not afraid of death, and able to upgrade through battles, improve attributes, and even directly buy various exaggerated magical abilities!

“To tell you the truth, the naval headquarters, the sea emperor of the new world, the master of the underground world, and even the top leaders of the cp0 and the revolutionary army, have my people.”

Before the war in Wano, Liu Yejin took Nami’s hand mysteriously, and said to Nami, “Don’t be afraid, no one dares to touch you with your brother’s backing.”

- Description from novelbuddy

Perhaps it is the choice of fate. As a senior otaku, Qian Lingfeng got the “steel shell system”. However, when he swept the world with the system, became a local rich man, made all kinds of beautiful women, opened a harem, and realized the ultimate fantasy of thousands of otaku, he found that things seemed far from simple!
When the end comes, biochemical zombies suddenly come down, fierce beasts are in power, bloodthirsty zerg roam to kill the world, and human lives are comparable to dirt. Where will weak human beings go in this world? Is humanity going to be extinct? Or … can an otaku save the fate of the human race?

- Description from Novelupdates