Naruto: Systematic Shinobi - Chapter 34: Number Seven: Fu - 1

When the heavy curtains of night descended, darkness fell upon the earth. What will later be known as the dawn of the “Dark” era, humanity once again unfolded a new path of evolution. While retaining the memories of surviving ten years in the apocalyptic world, Ye Chen awakens back on the very day the disaster struck; all he can do is protect the people dear to him, and then….

With the might of an ant, set foot upon the pinnacle of this world!

The people lost in the thralls of everyday life, aimlessly struggling for survival in this world, move forward; there will surely be a path only you can open….

- Description from Novelupdates

Freely traverse between the city and the abyss, cultivate a demon legion! Command demonic talents!My name is Bai Yan, from that day on... one of my souls possesses two identities.I am a demon! Also a human!When I am good, I benefit the world! When I am evil, there are corpses everywhere!

Xue Xi is forced to fall in love at first sight with this dangerous man on their first meeting. With death being the only other option, she makes the first move:

In 1930s Canada, a 16-year-old landlord unlocks a System unlike anything this world has seen—a power that lets him grant supernatural abilities drawn from warriors of another realm. Barbarians, Archers, Wizards… all under his command.