Well, it depends on how the author has designed the magic system in that fanfiction. She could inherit the ability to communicate with certain magical creatures in a very special way. Since Harry Potter has always had an affinity for magical creatures, and if Elena has some connection to them as well in the story, this could be a really interesting magic for Fem Harry to inherit.
In the fanfiction, Fem Harry Potter's life at Hogwarts as Elena's daughter would be full of unique experiences. For starters, she may have a special dormitory or living arrangement. Maybe she has a private study area or a special room where she can practice magic that is related to her heritage. In terms of classes, she could be given special projects or tasks that are related to Elena's magic. For example, if Elena was known for her potions - making skills, Fem Harry might be asked to recreate some of Elena's famous potions. Socially, she would be the center of a lot of attention. There could be a group of students who are always trying to be around her to learn more about Elena, and this could lead to some interesting friendships and rivalries. Also, she might have some special privileges like early access to the library's restricted section if Elena had some connection to the library in the past. This would give her an edge in her studies but also make her a target for those who are envious of her special treatment.
Yes, there are likely some fanfictions with this concept. Fanfiction often explores wild and creative crossovers. Writers might be attracted to the idea of combining the magical world of Harry Potter with the Norse mythology of Loki and creating a unique story where a female Harry Potter has this unexpected connection to Loki as his daughter.
She might start using black magic out of a sense of desperation. Maybe she feels she has no other way to achieve her goals, like protecting her loved ones or getting revenge on her enemies.
She might inherit enhanced physical abilities like superhuman strength, speed, and agility. Sesshomaru is a very powerful demon, so Fem Harry Potter could also have the ability to sense other magical beings from a distance. And perhaps she could inherit some of his demonic energy which could be used to enhance her spells or protect herself in a different way than normal wizarding magic.
If Hermione was Maleficent's daughter in fanfiction, she could inherit Maleficent's dark magic - based powers. This might include the ability to create powerful curses, although Hermione, being the character she is, would likely struggle with the moral implications of using such powers. She could also inherit Maleficent's power of flight. In the original stories, Maleficent can fly using her wings or magic. Hermione could potentially develop a magical form of flight, which would be a great asset in her adventures and her ability to quickly get to places in the wizarding world.
One possible plot could be that Fem Harry Potter discovers her true parentage as she grows up in the wizarding world. This revelation could cause chaos as she tries to understand her place between the two very different worlds. She might have to learn about her Norse powers in addition to her magic, and face challenges from both sides.
It might enhance her charm - related magic. As a succubus has a natural allure, her spells for persuasion or distraction could be stronger. For example, she could use a modified version of the Imperius Curse more effectively.
Her personality might be different too. The chaos within her could make her more impulsive and free - spirited compared to Harry's more cautious and sometimes self - doubting nature. This could lead to her making different decisions in similar situations. For example, when faced with a dangerous magical creature, instead of trying to find a strategic way out like Harry, she might try to use her chaotic powers to directly confront it.
She could use a magic - suppressing charm. This charm would make it so that her natural magical aura is hidden from other wizards and even from magical detection devices. For example, if a wizard were to pass by her with a magical detection spell active, they wouldn't sense her magic. Another way is by only using very basic and small - scale magic when absolutely necessary. Like if she needs to light a candle in a power outage, she might use a very tiny and discreet fire - making spell that looks almost like a normal match being lit.
One great fanfiction could be 'The Hestia - Bound Potter'. In this story, the fem Harry Potter as Hestia's daughter discovers her unique powers related to the hearth and home magic. It shows her journey through Hogwarts, facing challenges not only from the dark forces but also from the doubts within herself about her new identity.