Cyberpunk: Ultimate Cyborg System - Chapter 1: Prologue.

Frank, a mercenary known for his cold ruthlessness, decides it’s time to leave the bloody world of the underworld behind. But the underworld has no plans of letting him go. Relentless enemies from his violent past keep hunting him, and eventually, they succeed—Frank is killed.But fate has other plans. Instead of staying dead, he is mysteriously reincarnated into the body of a cop in a world filled with crime, corruption, and dark secrets. With the help of a strange, all-knowing system, Frank is given the chance to live again—this time, to prevent crime before it happens.

She, the “godly doctor” of an assassin organization in 21st century, transmigrated into the body of Yun Family’s abandoned, good-for-nothing Ninth Miss. Good-for-nothing? Then she’ll let the world see what a real good-for-nothing looks like. Summoners are legendary? Nothing is impossible in this world! She’ll become the first Magical Summoner.

He, the third prince in Long Xu Kingdom and the mysterious, behind-the-scenes owner of Zhou Dynasty’s monopolized business, seemingly handsome and uninhibited, is actually brutal and merciless.

The world knows her as a sickly good-for-nothing and her standing is as low as a servant’s, yet she solely dominates his heart. Trickery, schemes, overbearing, seducing… an exhaustion of methods, all to capture her heart. The scheming couple supports each other, producing stories about enmity, love and win-win cooperation.

Read to see how they stand side-by-side at the peak of this extraordinary world.

- Description from Novelupdates

…but it seems pretty doable.

Ryouma Takuma, a 39 year-old man with a hidden past, finds himself in a strange white room. There the gods tell him that he has died and that they are sending his soul to a different world; a world where magic exists. After living alone for three years his gamer soul loses common sense and starts toward crazy routes.