My name is Yan Xing. I'm an Earthling who can travel freely between Earth and a world of magic.
The elves love the silk I bring them, and they love the longbows and rockets I give them, too.
The orcs love the soap I bring them, and they love the Growler tanks I give them, too.
While human nobles are going crazy over pristine porcelain, they also install a few Tesla coils on their estates.
Even the undead want to order a set of fine coffins from me, so they can watch horror shows when they can't sleep.
One day... angels, dragons, and demons come looking for me.
I tell them, “My market is open to every race and creature. How about a few portable End-of-the-World Judgments?”