I'd hate to be that person but I don't do well with modding, it's not really something I can really do with ease like anyone else so I'm kind of a outcast in this community so I preferred to wait until someone just reveals their own modded version so I wouldn't have to
its super duper ez. Did you manage to download mugen hyper edition? because thats step one.
Step 2. Go to Hentai Char mugen and find characters you want. Download them. (i recommend making a new folder for them as a destination)
Step 3. Click the mugen hyped edition folder and look at all the stuff in it.
Step 4. Find the "Char" folder
Step 5. Manually move the downloaded characters folders into the char folder (you can glance around the folder to see an example)
Step 6. Click the "Data" folder
Step 7. Click the "MMMD" folder thats INSIDE the data folder
Step 8. Click the "Vselect" program inside the MMMD folder.
Step 9. Once the program opens up, all you need to do is click the squares where you want to assign characters. After clicking a square itll ask you to assign a char. manually type the name of the char folder they came with (for example "Lusty Male Charizards" folder was written as "Lusty_Male_Charizard")
Step 10. click save at the top left of the program, then close vselect
Step 11. Open Mugen, and enjoy!
I recomend adding maybe 1-2 characters at a time, simply to track if theres an issue with any misspellings in the vselect assignment.