One great Izuku quirkless fanfiction is 'A Different Path'. It shows Izuku finding his own way to be a hero without a quirk through sheer determination and intelligence. He uses his knowledge of hero strategies and martial arts to hold his own against quirk - users.
Definitely not. Midoriya's character is very much alive in the manga. The creators have no intention of killing him off as he's a key figure in driving the narrative forward and inspiring other characters.
His closest friends like Ochaco Uraraka and Tenya Iida would most likely side with him. They have always been there for Midoriya and share his values of justice and doing what's right. Also, those heroes who have seen Midoriya's growth and believe in his pure intentions would probably join his side.
One interesting quirkless oc fanfiction could be about an ordinary person in a world of quirks who uses their wits and determination to outsmart villains. For example, they might study the weaknesses of quirk - using opponents and use strategic planning to achieve victory.
In fanfiction, the relationship between quirkless Izuku and Jirou can be really interesting. They might bond over Izuku's determination despite not having a quirk. Jirou could be drawn to his tenacity and unique perspective. For example, Izuku might help Jirou with her insecurities about her quirk, and in return, Jirou could support Izuku in his battles, not just physical ones but also the mental battles he faces as a quirkless hero - in - training.
The idea of Izuku being quirkless is appealing because it's a story of the underdog. People love to see someone who is at a disadvantage rise above. In the original story, Izuku has a quirk in the end, but in fanfiction, keeping him quirkless allows for a different exploration of his character. It shows his tenacity and his ability to find solutions outside of the norm.
Maybe in this fanfiction, Midoriya as a girl discovers new aspects of her power. Since her body has changed, the way she channels her quirk might also be different. She could then have to train all over again to master this new way of using her ability.
Inko Midoriya remains alive throughout the manga. The story doesn't involve her death. Her character plays an important role in supporting the protagonist without facing such a fate.