BookBarbarian
Expert Long Rester
I think Ethan Rayne would disagree on your perception of 'Ripper's' alignment.
The Mayor, though a villain, seems to also have some shades of gray. He has a loving father-daughter relationship with Faith and is very well mannered. I think both characters (and most other characters in Buffy) defy the generic alignment system of D&D.
Many evil people can love others. For example some serial killers had families that would never have guessed that their husband/father was living a double life. A single loving relationship does not tip the scales a way back to neutral when compared to orchestrating dozens/hundreds of murders and willingness to commit as many as is necessary to achieve one's goal.
The Mayor's relationship with Faith is meant to make this very evil character relatable and compelling. And it did that very well.