The One Who Writes Existence - Chapter 21: System, A piece of !!!!

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:

The Celestial Express is a train that goes from one galaxy to the next, picking up passengers along the way.Its Navigator, the one who drives it through the stars, is a god who can grant those passengers wishes.Jax arrives on the Celestial Express with no memories but a single wish—to save someone. After learning what the Navigator is capable of, he decides to go find him.To find the Navigator, he must go through TEN different Carriages, all of which contain a world of their own.And, he must do it with a restriction called Single Spell Sorcerer.

On his coming-of-age day, Argolaith’s mistake bound him to a mystical magic unseen in the world. As his powers grow, they threaten to reshape the realm—but can he master them before they bring ruin?

A back-to-basics(?) monster evolution novel.