How about I replace the ficticious Ni Ngyun name with this one...Taun Nguyen?
Try again. You found Nguyen but what is that in front of it?? You can't just make up names for a culture with another language, especially a culture that uses a Roman script. A certain group of Americans makes up anything to be a name but it doesn't work in Vietnamese. There is a limited group of family names and the given names all mean things- they are not just syllables that sound nice or look nice.