One great Naruto fanfiction involving Edo Tensei and Hashirama could be 'The Reawakening of the Sage'. In this fic, Hashirama is brought back by Edo Tensei in a different scenario than in the original series. It explores his interactions with Naruto and how his ancient wisdom impacts the modern ninja world.
Many fanfictions also touch on the theme of the afterlife. Since Edo Tensei is a form of resurrection, questions about what it means for Madara to be brought back, and how it relates to the afterlife in the Naruto universe are often explored. There could be stories that delve into his relationship with the person who resurrected him and what their end goals are in relation to his Edo Tensei state.
One great Naruto Edo Tensei Madara fanfic is 'The Resurrected Conquest'. It really delves into what Madara could have done if he had more time during his Edo Tensei state. The story has some amazing fight scenes and really captures Madara's character well.
Naruto might initially be on guard and hostile towards Edo Tensei Madara. But as Naruto is, he would also try to understand Madara's motives. He could start by trying to talk to Madara, asking him why he still clings to his old ways even in his undead state.
A plot that stands out is when Hashirama, through Edo Tensei, has to team up with modern - day ninjas against an ancient evil that has been resurrected. It's interesting because it combines the old - school power of Hashirama with the new techniques of the current ninja generation.
The popularity of Naruto Edo Tensei Madara fanfic lies in the character of Madara himself. He's such a complex and powerful character in the Naruto universe. When brought back by Edo Tensei, it adds another layer of intrigue. Writers can explore different scenarios with him, like how he would interact with the modern - day ninja world.
One possible interesting plot could be Madara, in his Edo Tensei form, somehow regaining his full power and challenging Naruto not in a fight to the death but in a battle of wits. Naruto, on the other hand, tries to find a way to either seal Madara permanently or make him see the error of his ways. For example, Naruto could use his talk - no - jutsu to try and convince Madara that his quest for power has only led to destruction.
You can try fanfiction websites like FanFiction.net or Archive of Our Own. Just search for 'Naruto Edo Tensei Madara' on their search bars, and you'll be presented with a variety of fanfictions. Some might be action - packed, focusing on Madara's battles during his Edo Tensei state. Others could explore his backstory or his relationships with other characters in new and interesting ways.
In certain fanfic concepts, Naruto could learn Edo Tensei from Kabuto. Kabuto, having mastered the jutsu, might decide to teach Naruto for some reason. It could be because he sees Naruto's potential to use it in a more positive way compared to how he misused it. Naruto, with his strong sense of justice, would then try to modify the jutsu to be less evil - like not using it to bring back people against their will.
There's also a possibility that it could be an unknown villain. A new character created by the fanfiction author who has a vendetta against Konoha or the ninja world in general and believes that resurrecting Naruto through Edo Tensei would be a way to start some sort of revolution or destruction.