Let's see what I can remember of the backstory for Rita Wulf the character.
She's an old species of werewolf from the area of the north that would eventually become scandinavia. Her village was attacked by a frenzied beast when she was a young adult. They managed to kill it by knocking it into the fire, but the attack cost a lot of lives. She was one of the survivors, making what seemed like a miraculous recovery. Instead it was a curse.
The first time she turned was incredibly traumatic for her. She managed to get away from her village, away from her family, but she doesn't remember much, if any of it. The trauma is the only thing that stuck with her. She has never been able to shake the belief that she was/is cursed, even though she doesn't think the same of any of her family born from her.
Because of that trauma she is extremely hesitant to turn anyone else. Having children the regular way is fine by her, she even feels proud about being a werewolf, but actually turning a non-werewolf into a werewolf the same way that happened to her is extremely unpleasant to even think about.
She doesn't actually know how old she is, because she remembers almost nothing from her early age. Whether she wandered around for years, decades, or centuries is unknown to her. At her best guess she is at least 5000 years old, but it could be more. Part of her would rather not remember in case all of that time was filled with atrocities she caused in her beast form.
Eventually she was found by another werewolf who taught her how to control herself. How to stay in control. After that training was over, she could finally walk away to start a new life. But there has always remained a nagging thought in the back of her head that maybe the person she is now is not the same as who she was before she lost her mind. That she had found a different mind, rather than her original one. (trans allegory?)
As time passed she evolved from a fairly regular werewolf to a more general shapeshifter. She could change her appearance freely, no longer bound by the moon, or forced to only use wolven forms. Though she retained some of her werewolf traits, like she still feels a pull towards the moon, and she is weak to fire. Her healing factor is so strong that she can rapidly recover from practically anything, even apparent death. It's what makes her immortal as well. Even signs of aging get healed.
Fire is the main thing that counters her self-healing ability, basically slowing it down to not much different from a human's. Perhaps a little better, but not drastically so.
As a possible side-effect of this she is always hungry. She's become used to it, so it's not like it controls her, but it's always there. That is probably what led her body to adapt to be able to eat basically anything. Even things that would be considered inedible, or hazardous to any other species. Basically her entire body is able to devour, so any parasites or the like that try to enter her body are doomed. Though she still feels embarrassed about the time she ate someone's table.
She has had various encounters with beings that gifted her special forms she would never have been able to change into through normal means, and occasionally she likes to flex by using them.
She can handle most weapons uncannily well, even if she's never seen them before, but her preferred weapon is a spear, or at least some form of polearm. Even though she'd probably be much more effective just relying on claws, and fangs.
She is also an accomplished mage, even though she doesn't have a great aptitude for it. She's just had lots and LOTS of time to work on it.
In contrast other forms of technology don't get along with her. She is hopeless with anything resembling modern tecnology, and thinks her curse ruins any electronics she touches. Even though it's more likely that's just her old-person mentality. She long ago stopped feeling embarrassed about asking her kids to handle that stuff.
Having no memory of her own name, she chose the name Wulf when she wanted to start her own family. She currently has twelve children, all at least a century apart in age, a lot of grandchildren, and so on.
For some reason I don't remember if I ever specified, shortly after having her third child, the entire family, the Wulf Clan as they had become known, left Earth (which she still refers to as Tellus) via portal magic she had developed.
In order to find a place for herself, and her family, she decided to turn the Wulf Clan into basically a mercenary company. Her strength, and fighting ability was what she had the most confidence in. They became infamous for their ruthless efficiency, and many came to curse "The Clan" for their actions.
Still, her plan largely worked. The Wulf Clan grew in wealth, power, connections, and influence. Having more children, and grandchildren, was basically just adding more forces to the company. Looking back on it, she's not proud of that part of her life.
Her wakeup call came when her eldest got lost in bloodlust, and went on a megalomanical rampage saying he wanted to take over the galaxy. Killing anyone in his way, or even his proximity. Due to her sense of responsibility she felt forced to put him down herself. There was hardly anyone else strong enough to deal with it. It was the second biggest trauma she suffered.
After that she pulled out of the mercenary business, and tried to do what she could to distance herself from that chapter of her life. While to others her sense of morality probably seems rather grey, to her it's pretty black and white. She divides existence in family, and non-family. Family doesn't just mean those blood-related to her, but also extends to friends, and allies. Family should always be protected with all her might, while non-family doesn't really matter.
This situation really shook her, and made her finally confront that all she had brought to the galaxy was misery. She didn't condone slaughter without good reason, but she had never helped someone without compensation either. In this case she hadn't been able to work things out as she wanted. She could try to justify to herself that her son had fallen into the same frenzy that had once claimed her, and she had certainly wanted someone to stop her when she was like that. But all excuses felt hollow.
She made it her mission to try to do things that helped people instead, whether they were family or not. That even if people hated her, maybe she could at least try to redeem her remaining children. Let them lead better lives.
Her main contribution was the formation of what would eventually be called Gate Inc. With the help of her more tech-savvy children, she was able to combine her self-made portal magic with technology to create Gates. Massive structures, which I based on the idea of Stargates, that could instantly connect two locations with a stable portal that allowed free travel, and trade between distant worlds.
Considering the Wulf Clan's reputation it wasn't easy to find people willing to work with them, but eventually they were able to build a respectable business, and reputation out of it. There were still plenty of people out there who hated them, so they had to remain wary of attacks on the Gates, but things were improving.
Rita decided to step down from any sort of leadership position besides matriarch of the clan, and left the business to her oldest daughter Jennifer. She stopped making public appearances outside of when a new Gate was near completion. She would always be there to make sure it started properly, since only she had enough magical power, and knowledge of this particular magic, to make it work. But otherwise she was almost never seen. With time Rita's reputation became more of an eccentric, which she preferred over being thought of as a villain, regardless of whether she thought she deserved it.
That the fear she had once instilled in people had largely faded away was good enough.
Stepping down allowed her to focus more on her family, and dote on them to an extent that several of them likely found annoying. She also started travelling. There was so much she had never taken the time to really see, and now she had the time. As incognito as possible. Being able to change her appearance to whatever she felt like was a big help.
She also finally made her way back to Earth (Tellus), which she hadn't seen in a couple of millennia. It wasn't somewhere she had a place any longer, but she still held a fondness for it.
I guess that's it... honestly more than I expected. I did sort of build up an entire mythos, with her current day self basically just walking around with an outlook that switched between playful vixen, and doting grandmother, depending on the situation. She finally felt some genuine curiosity about life, the universe, and everything.
But she would still step in whenever anything threatened her family. If people had forgotten why she used to be so feared, they would learn it again the hard way.