The Interworld Trader

[Travel Between Two Worlds, A Variety of Abilities] Gradual power progression

Qin Shen, a homebody in the modern world, suddenly gains spatial powers. As long as he has the coordinates for a location, he can go wherever he wants.

At first, he develops his abilities in a world much like ancient times, except that it is also home to elves and beastfolk alongside humans.

He could have simply traded goods between the two worlds and lived a wealthy life, but suddenly, BA particles surged in the modern world, causing many species to mutate. Everywhere outside human settlements became fraught with danger, and the government kept the news under wraps to protect the public.

As Qin Shen watches humanity's habitable territory steadily shrink, he has no choice but to step forward.

More and more people with supernatural abilities begin to emerge in the modern world. Their powers vary, and they are classified into ranks from F to S.

This story is sweet and mostly slice-of-life, though it gets a little angsty later on.