Sure, in the 'Fairy Tail' universe, the concept of Natsu being END is quite fascinating. Fanfiction writers often take this idea and run with it. They might create stories where Natsu discovers his true nature as END more gradually, or they could write about how the other guild members react when they find out. It can also lead to stories that explore the origin of Natsu as END and how it ties into the overall lore of the 'Fairy Tail' world.
Natsu's character development in this fanfiction might involve him becoming more responsible. With his end form, he has greater power and with that comes the need to use it wisely. He could start to think more about the consequences of his actions. For example, he might not rush into battles as blindly as he used to. Also, his emotional growth could be a part of it. He could become more in tune with his feelings towards his friends, especially Lucy. His loyalty to the guild could also deepen as he realizes his new form can be a great asset to protect Fairy Tail.
In some fanfictions where Natsu becomes END, it often leads to a power - up that is both amazing and terrifying. His physical appearance might change, with more demonic features. His power level could skyrocket, making him one of the most powerful beings in the Fairy Tail universe. He might struggle with the newfound darkness within him, as END represents a very powerful and potentially evil force. This could lead to interesting storylines where his friends in Fairy Tail have to find a way to bring back the Natsu they know while still dealing with the power of END that he now wields.
In this fanfiction, Erza and End Natsu are central. Erza is a powerful mage from Fairy Tail. She has a sense of justice and is not afraid to take on challenges. End Natsu, with his potentially more menacing and unpredictable nature, makes for an interesting counterpart to Erza. Their meeting and the events that follow will revolve around their personalities and abilities.
Well, it could be about a powerful encounter. Maybe Erza initially mistakes End Natsu for the regular Natsu and there's some confusion. Then they might have a fight as Erza is always ready to combat threats. But as they engage, they could discover things about each other that change their views.
Fanfiction.net is also a good place. There are many different stories about different fandoms. You need to search specifically for 'natsu and fem end lemon fanfiction' though. Sometimes, you might have to dig a bit deeper through the search results to find the ones that really interest you.
One popular 'natsu and fem end lemon fanfiction' might be 'A Magical Encounter'. It has an interesting plot where Natsu and the female character go on an adventure together and their relationship develops in a unique way.
I'm not sure who exactly Natsu is just from 'natsu reads fanfiction'. It could be a normal person who just enjoys reading fan - made stories. Maybe it's a nickname for someone within a particular fan community.