There could be a 'anna has powers fanfic' where her powers are related to nature. For example, she can communicate with animals and make plants grow rapidly. This leads to her having to protect the natural balance when some dark force tries to disrupt it. She teams up with other characters who also care about nature and they fight together.
One great 'anna has powers' frozen fanfic could be about her using her new - found powers to save Arendelle from a mysterious and powerful threat. In this fanfic, she might have to learn to control her powers quickly and make tough decisions along the way.
One plot idea could be that Anna discovers her fire powers in a time of great danger for her village. She has to quickly learn to control them to fight off an invading force of ice creatures. Another could be a story where Anna is ostracized because of her powers at first, but then she uses them to save a friend who didn't believe in her, thus winning back the trust and friendship of those around her. A third idea is that Anna is transported to a different realm where her fire powers are seen as a gift from the gods, and she has to use them to help the people of that realm defeat an evil sorcerer who has been oppressing them.
One possible fanfic could be about Anna discovering her fire powers in a hidden part of Arendelle. Maybe she stumbles upon an ancient relic that unlocks this power within her. And then she has to learn to control it to protect her kingdom from new threats.
Anna's fire powers could be described as a searing blaze that she can summon at will. The flames might be a bright orange - red, with a heat so intense that it can melt ice in an instant. When she gets angry, the flames could flare up uncontrollably, reaching higher and burning hotter. She might be able to shape the fire into different forms, like a whip to lash out at enemies or a shield to protect herself. The fire could also have a unique quality, such as leaving behind a trail of warm embers that slowly fade away.
You can try fanfiction websites like Archive of Our Own. There are often a large number of fan - created stories, including those about Anna having powers. Just use the search function and type in 'anna has powers' to find relevant fics.
There could be a fanfic where Anna gets ice powers and she embarks on a journey to discover the origin of these powers. Along the way, she meets new characters and has to overcome various challenges using her ice powers and her strong will. This would add a whole new adventure aspect to the Frozen universe.
One possible plot could be that Anna discovers her fire powers during a dangerous situation, like when she's trapped in a burning building and suddenly realizes she can control the fire. Then she has to figure out where these powers came from.
One interesting anna nishikinomiya fanfic could be about her adventures in a new city. Maybe she discovers a hidden magical place and has to use her wits to navigate through it.
Maybe she discovers she has super strength and uses it to protect her town from villains.
There could be a fanfiction where Bella has the power of precognition. She can foresee events that are about to happen, especially those related to the danger that lurks around her. This power makes her a key figure in the fight against the Volturi as she can predict their moves and plan accordingly.