I wasn't going to post anything further on this site, but finally decided that others who are just interested in local creations may be looking for something like this. I was, but couldn't find it, so I made it. This is a wildcard for ethnicities, but is not your standard "black, white, Asian, Indian, etc" kind of wildcard that is both everywhere and completely useless at the same time. I broke this down by "racial regions" with each nationality identified and a general description given for that overall appearance. There is enough detail given that you can expand this wildcard from where it is if you need more nation-specific characters, just by using the details in it.
Beautiful Races V2 replaces and expands Beautiful Races V1, while still leaving room to expand the list into the various nationalities that make up the racial regions, if you need them. Beautiful Races V2 has been further updated to remove the issue with a few of the races creating the girls in a body of blue water and narrowing that focus back to their eyes.
Beautiful Mixed Races is a variety of racial mixes that are well-established and already well known.
Chinese Ethnic Groups is a list of the predominant ethnicities native to China.
African Ethnic Groups is a list of the predominant ethnicities native to Africa.
Indian Ethnic Groups is a list of the predominant ethnicities native to India.
Arab Ethnic Groups is a list of the predominant ethnicities native to the Middle East.
European Ethnic Groups is a list of the predominant ethnicities native to Europe.
Native Am Ethnic Groups is a list of the predominant tribal ethnicities native to America.
If you need additional racial mixing, I would suggest using Beautiful Races V2 as part of your prompt in the following manner: (beautiful_races-with_description-expanded:beautiful_races-with_description-expanded). Be warned, though, that the 84 racial prompts in the wildcard will create over 7K different images in this way, at minimum, assuming that you only generate one image for each variable. If you are searching for that "needle in a haystack" kind of racial combination, you are going to find it generated in one of those 7K+ images, but it going to take a while to find.
The sample images were all created using Snapfschuh's style of prompting.