Ugliness versus Characters with the "Inverse Appearance"

A character with Appearance 1 is so ugly or unimpressive that people tend to have unfavorable first impression. A character with Appearance 0 is hideous and always fails at first impressions.
Some monsters have the inverse Appearance trait. A monster with Appearance (inverse) 5 is not beautiful or handsome, but it is unspeakably hideous in a way that is so impressive that they can cow people into submission. Rather than their appearance stimulating feelings of disgust, it creates feelings of fear and submission. Appearance (inverse) 5 and Appearance 0 are probably equally hideous but the difference between them is the difference between “Ewww that’s gross!” and “Oh my gods, please don’t hurt me, I’ll do whatever you ask!”
Characters with inverse appearance are usually subjectively ugly but they can also be majestic and scary. Whether a dragon is beautiful or ugly is up for debate but a dragon's Appearance score dictates how impressive she is, not how aesthetically pleasing she is.  Dragons may be beautiful or ugly or both at once, but a high Appearance dragon can often cow others into submission with her visage alone while a dragon with a low Appearance rating will usually have to use a display of raw force is she wants submission.
If a creature with inverse Appearance reproduces sexually, in most cases what is considered inverse Appearance to outsider is treated like regular appearance among their own kind.  Both male and female monsters like to mate with partners who can cow lesser mortals with their presence.