Perhaps in the 'rwby pyrrha returns fanfic', Pyrrha returns with a mission to redeem herself. She could have made some sort of deal during her absence that now requires her to complete certain tasks to save Remnant. This would involve her working with RWBY and other allies, while also dealing with the mixed feelings her friends have about her return.
Since we should avoid inappropriate content, let's consider the more positive plotlines for Pyrrha in a Yuri - themed RWBY fanfiction. One plotline could be Pyrrha forming a deep emotional bond with another female character during their training at Beacon Academy. They might support each other through difficult times, like facing tough Grimm battles or dealing with academic pressure.
For Ruby, Pyrrha's return could be a huge boost in morale. Ruby has always looked up to Pyrrha, and having her back would give Ruby more confidence in their fight against the Grimm. Weiss might be a bit more skeptical at first, but eventually warm up to Pyrrha again as she realizes how much they need her. Blake could see Pyrrha as a symbol of hope and a reminder that they can come back from difficult situations.
One possible plotline could be Pyrrha dealing with the trauma of the near - death experience. She might struggle with PTSD and have to work through her fears in order to get back into the fight. Another plotline could involve her relationship with Jaune. Since she survived, their relationship could develop further, perhaps leading to a more romantic connection. She could also become a mentor to the other students, using her own experience to help them grow and become stronger fighters.
Often, in these fanfictions, Pyrrha comes back and has to deal with the aftermath of her 'death'. She might have to regain the trust of her friends who thought she was gone. There are also plotlines where she returns with new powers or abilities. For instance, she could have gained powers from the place she was 'preserved' in while she was 'dead'. Some stories also explore her relationship with Jaune again, now that she's alive, and how they pick up where they left off or start anew.
It's hard to say exactly where Pyrrha is without knowing more about the fanfic. She could be in a distant land, trapped in a dangerous situation, or simply lost and trying to find her way back.
One interesting plotline could be Ruby and Pyrrha teaming up for a special mission. They might face a powerful new Grimm together and have to rely on each other's unique skills. Ruby's speed and scythe - wielding abilities combined with Pyrrha's combat proficiency and semblance would make for an exciting battle sequence.
A really interesting RWBY Pyrrha fanfic is 'Pyrrha: The Untold Stories'. This fanfic explores her backstory in more detail, like her early days at Beacon Academy and her relationships with her classmates before the main events of RWBY. It gives a lot of depth to her character.
A good RWBY Pyrrha fanfic should stay true to her character. Pyrrha was strong, yet kind - so the fic should reflect that. For example, if she's in a fight scene, she should use her skills in a way that's consistent with the show.
One possible plotline could be that Cinder discovers a pair of garnet pants with some sort of magical property. Maybe the pants give her an extra boost in her combat abilities, and she has to keep it a secret from the other characters while using it to her advantage in battles against RWBY and their allies.
One possible plotline could be Torch Wick's return causing chaos within the existing power dynamics in the RWBY universe. Maybe his return disrupts the balance between the different academies and the Grimm forces.