So I came up with an au idea after checking out the TADC opposite au. And for the first designs of the au, I decided to start out with Bella and Evelyn first.

Bella in the original universe is kind, sweet, and very forgiving. But in this universe... she's a complete different person.

Due to the death of Evelyn and the demise of her father, Bella came from being a naive and over friendly demon to a vengeful soul, furious at the many people that wronged her.

While not evil, Bella harbored a deep hatred towards Stanford and Stanley Pines, and often found ways to torture them in an act of revenge.

Dipper had spent days trying to seek out Bella's forgiveness, which took a month to do so, since the demon was almost unforgiving. Though, Bella can sympathize and forgive someone to some extent, it's not always easy to earn her forgiveness.

Due to her endless rage, Bella is always in her rage form, seen way more with red skin than yellow by most of her peers.

Unlike her canon self, Bella is not a pacifist. Once you try to mess with her, she'll either give you a deadly threat or, quote, "rip your arms off".

Bella isn't all that bad though. Like her canon self, she has a bunch of lovers. This kind of fact often surprises most people due to her temper and tendency to act out in violent ways.

Her lovers are pretty much the only people she's very much more affectionate and loving towards. Do anything to hurt them, and she'll put you in a world of pain.

Bella grieves Evelyn as much as her canon self, so much that she stopped wearing her old black bow and began wearing Evelyn's to remember her by.

As for Evelyn...

Evelyn never really wanted to be an exorcist. She only joined because she felt she had to for her parents' sake.

Evelyn isn't exactly the bravest warrior there is, not to mention that she pretty much is more of a pacifist than a fighter, and prefers to avoid conflicts than to start them.

Evelyn isn't very trustful of the mascots, she pretty much goes along with Bella's beliefs. Unlike her canon self, her death was the result of an freak accident and not a murder.

Evelyn cares about Bella very much to the point that she worries about her not knowing her father's true nature, that she tries to expose the truth and lead her onto the right path.