Aki Daidaiiro

Aki Daidaiiro was created by the user Ireallydonthaveaideaforausername. She's supposed to be a joke character that is a dark magical girl, and is an American teenager over-obsessed with Japan so much, that she ended up giving her soul to Kyubey to become a mary-sue.

Although she wasn't specific on what exactly she wanted, Kyubey did grant her powers. Basically, now, she is an mary-sue who can use lots of healing powers, but she is heavily tsundere, to the point of being downright abusive to other people.

Backstory
When she was a preteen, she had an unhealthy obsession over anime and manga. She was the oldest in her younger siblings.

Until suddenly, one day, when her family was eating inside a restaurant that was very high-class, one of the chefs accidentally burnt down the restaurant. The only one that survived was Aki Daidaiiro, mainly because she wanted to become the most powerful being.

Aki was at first amazed by his power, until... she discovered that she couldn't turn herself Japanese. Sure, she had amazing healing powers and was utterly immortal for the rest of her life, but she can't turn herself Japanese.

She tried arguing with Kyubey about this, but Kyubey straight up asked "I could've made you into someone that actually loved themselves, not wanting to change themselves because of fictional media."

At this point, Kyubey revealed to Aki, that the reason why he knew, was because of the fact that her purse at the time had an anime keychain. "Maybe if you weren't wearing that, and phrased that question a little differently, I wouldn't have known your personal preference of cartoons."

Aki was pissed, but she left Kyubey alone. She regretted making that wish.

Currently
Nowadays, she's an overly abusive tsundere girl. She often works alone, because of her incapability to work with other people.

One of the many things she represents is envy and wrath. Of course, she had a rough childhood, but that gives her no excuse to act this way. In fact, many of the people that know her, think she's a bitch to everyone. What they don't know is, that Aki would be acting sweeter if she became Japanese due to her being obsessed with Japan.

Due to her being immortal, she has been trying to find her meaning of life; becoming Japanese, even though she knows it's impossible.

Even with her powers making her immortal, this is ultimately her downfall, primarily because she's an failure in everything else.

She lives on with one person. Herself. She defeats witches and saves people from suicide, often demanding money from them or else. That's how she survives, and she's well above making more than enough to survive on her own.

Personality
Her personality often consists of her being rude, and threatening to others. This is very obvious.

What you don't know is that, very rarely, she can be generous. She'll occasionally further help the people that she saved from "suicide" (Which is just witches trying to kill people)

Of course, usually she's trying to be generous to gain more money from people. Whether it be because she's bored, or just wants to help someone to do something is usually why.

And yes, you can't forget about her obsession with Japanese culture; primarily anime and manga. Occasionally anime-styled video games.

Trivia

 * The creator allows anyone to use this character, as long as the creator is credited somewhere.