Return of the Calamity-Class Death Knight - Chapter 322

Born naturally defective but possessed by the spirit of a divine dragon. Inheriting the divine dragon’s will and power, growing scales and magical claws, imperial waters containing the breath of the dragon, travelling through clouds and summoning rain, an invincible physical body. In this world and era, countless men dream of slaying dragons. Li Mu Yang has always lived a hard life.

“You need my help, Tesoro. You choose. A marriage with me or be torn apart by them” His voice was cool as though this wasn't a matter of life or death.I didn't want this life. My father had gambled a lot and left me with a lot of enemies and now I needed the help of Don Vincenzo LaRosa who was my high school bully and now the Don of the most powerful mafia family in Italy if I was going to survive it.It was just a marriage of convenience but I realized something. He wasn't helping me out of a good heart. I had been sold without my permission to him. I was the mafia's pawn.

If you had a chance to live again, what would you do? Earn money, hold onto a thick leg, just find someone to live a happy life with? Ha ha… Stepping on the beat of the times, riding the wind and breaking the waves, strategizing, using your knowledge to change yourself, and everything around you, come back! The reality flows to the plot, the golden fingers are thick, slow, and cool.

- Description from Novelupdates

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