Don't take it personally kid, no one knows how to define that sort of thing.
Considering the fact that there are probably millions of people who essentially write either in the hopes of making or to make a living that we've never heard of, I don't think anyone knows if Kishi is "average", "exceptional" or what. It really just comes down to whether or not you like the story.
Some people like the Lord of the Rings series. I hated it. To me it was an "average" piece of work if you can even define such a thing. Yet people go nuts over it. I say if you came make a good majority of the masses appreciate your work, then you must be doing something above average because the average number of writers aren't known for anything at all. Hell there are unknown published authors