From A Stronghold NPC To The Final BOSS - Chapter 1057 - : Sanctimonious

Several hundred thousand players are trapped in a gritty zombie apocalypse survival game just after game launch. There are hints that deaths in the game might be serving some other terrible purpose in the background of reality…

The main character, Liu Gan, is a quadruple amputee in real life. A quirk in the server code recognized his prosthetic limbs as ‘real limbs’ in game, giving him ‘normal’ arms and legs that nonetheless have the strength and power of steel limbs, and thus far more power than a normal player. With this minor cheat helping him survive the early stages of the game, Liu Gan sets out to find out what exactly is going on, and to endure as long as he can.

- Description from Novelupdates

Ryo Tanaka, a struggling college student, works tirelessly at multiple part-time jobs to make ends meet. In a bid to earn some extra cash, he volunteers for a paid drug research study, unaware that it will alter the course of his life forever.The experiment takes a disastrous turn, leaving Ryo bedridden with a high fever for several days. But when he finally awakens, he finds himself in a world plunged into chaos. A deadly virus has ravaged the city, turning its inhabitants into ravenous, flesh-eating zombies. Streets once bustling with life now lay desolate, the remnants of civilization crumbling under the weight of the apocalypse.

She was originally the young miss of the Marquis Estate, but became a peasant girl due to a mixed-up at birth.