How to create a Hideous Antagonist?

Disgust the Public

You can easily interest people into delving in these topics if you choose the theme properly.
In most situations, if you offer an Explanation and eventually Solution Hypothesis it should keep the Public interested.
Because you display consistency & coherence.

The Sexual Criminal
Animated by short termism & immediate gratification.
Often motivated by inherent Sexism & Homophobia.
Can be combined with any other Paraphilia.
The actions of this characters can be foreshadowed by comments on another specific character.
May or may not act in group, used to determine the level of cowardice of the character.
The Sexual Crimes are often depicted.
However, you may prefer to deal with the consequences of the act, and namely the evolution of the victim’s life.
It would make your story more long term & character oriented.
Proxenetism & Pimping are rarely presented as Sexual Criminality, though they are acts of sexual exploitation.

The Cannibal
This Character finds a Sense of belonging in the flesh.
Namely the flesh on her kind.
Most of the time this one Lost her own Humanity to the flesh.
Should she be Physically Recognizable?
Should she be Branded?
Should she have a mark indicating her status?
This Character has been fairly used.
Though it wasn’t used in many different manners either.
Questioning the origins of her canibalistic nature is where you can create the specificity of the character.

The Eugenicist
Xenophobia industrialized.
The world has taken too much diversity.
So much so, that no order is possible.
This character is a subset of the Zealot.
Her main goal is to impose a Human Template.
Generally it is based on Ethnicity, but xenophobia can extend to any trait the Character views as Undesirable.
All depends of the Character’s sense of Arbitrary.
She does not necessarily cumulate all forms of xenophobia.
The Character can be Sexist without being Racist.
Though, it would be paradoxal that the Character was Sexist without being Homophobic.

The Fiend
The Face that could be put on top of all the others.
It isn’t a character in itself, but a layer.
Vanity & Pride are her main traits.
Not hypocrisy.
This one can act Honestly at all times.
A need to be in a Comfort zone of Recognition & Appreciation from other Characters.
Namely the Protagonist.

The Usurper
The Character hidden behind an ancient Ally.
The Betrayer/Traitor reveals herself after a crucial event.
The Betrayal must have heavy consequences.
This Character is defined by her lack of reliability.
This can be depicted early.
The propension to hesitate of this character is higher than the rest of the group.
Her repeated absences are remarkable.

Roughness of the Birth
How was the Character put into the World?
How was her 1st bed?
With who did she sleep?
- Until which age?
Who take care of her?
- In any way and according to this one’s definition of care

Early Childhood
Who fed the Character?
Who taught her basic skills?
What were these skills?
Are they still useful to her today?
What were her 1st Clothes like?
Did she possess any physical Object?
- An Object that mattered to her
Any of these characters can be raised in a seemly sane environment and later choose to diverge.

When where they exposed to their 1st traumatism?
Where?
Who was the aggressor?
Who was the victim?
Developing the origins of the Character’s trauma should not be construed as justification/legitimation.
Characters choose.
Even if it is up to the limits of their determinism.

Verbal
How is her Pace?
How is her Tone?
How is her Pitch?
What are her signature Words & Phrases?
- How often does she repeat them?
- In which situations?
- Who did she learn them from?