In fanfiction, Jiraiya's death can also be used to explore themes of sacrifice. He sacrificed himself for the greater good, and this can be further elaborated in different stories. For example, some fanfictions might show how his death inspired other characters to be more selfless.
Naruto is devastated. He feels a huge void in his heart. Jiraiya was the one who believed in him from the start, and his death makes Naruto question a lot of things. He might even start to doubt his own strength for a while.
At first, Naruto might isolate himself. He doesn't want to be around others as he is so consumed by his grief. He just sits in his room or goes to a quiet place where he can cry alone and think about Jiraiya.
One scenario could be that Jiraiya is poisoned before his fight with Pain. In the fanfiction, an enemy within the village who is secretly working for Pain's forces might have poisoned his food or drink. So, when he goes to face Pain, he is already weakened, and this ultimately leads to his death. Another possibility is that Jiraiya's death is a result of a time - traveling plot. If there is time - travel involved in the fanfiction, his actions in the past might accidentally create a situation where he has to die to preserve the timeline.
A fanfic like this might explore how fem Naruto's presence affects Jiraiya's typical behavior. Jiraiya is known for his pervy tendencies in the original series, but with a fem Naruto, he might have to control himself more. It could also be about how fem Naruto looks up to Jiraiya as a strong ninja and a source of wisdom, and how she tries to learn from him to become a great kunoichi.
Jiraiya might comfort Naruto by sharing his own experiences. He could tell Naruto about the times he faced difficulties and how he overcame them. For example, he might talk about his training with the toads and how he grew stronger through perseverance.
One great Naruto fanfiction with Edo Tensei Jiraiya could be about him coming back during a crucial battle. He could use his vast knowledge and powerful jutsus to turn the tide. For example, he might face off against an old enemy who has now become even more powerful. His return could also have a big impact on Naruto, as he could pass on some final teachings or advice.
One possibility in a fanfiction where Jiraiya is alive could be that he returns during the Fourth Great Ninja War. He could use his vast knowledge and powerful jutsu to turn the tide of the war. Maybe he teams up with Naruto again and helps him master new forms of the Rasengan or other powerful techniques.