Character development is key. Fanfictions explore how Ace and Luffy grow under Garp's influence. Maybe Luffy becomes more disciplined in some stories, or Ace learns to be more open - hearted, all thanks to their interactions with Garp and each other.
One possible plot could be that Luffy gets into a really tough situation during his adventures, perhaps surrounded by powerful enemies on an unknown island. In desperation, he calls out to Garp for help. Garp, despite his tough exterior, races to his grandson's aid. Along the way, he might reminisce about Luffy's growth and how far he has come.
Well, perhaps the plot could involve Luffy having to navigate a world where he is suddenly a girl. He might face challenges in how his friends perceive him now. Maybe he has to deal with different social expectations while still maintaining his goal of finding the One Piece. For example, some of his male friends might be overly protective or act a bit differently around him, and he has to figure out how to handle those new dynamics all while being in a female body.
One possible plot could be that Luffy, now as a girl, has to navigate the pirate world in a different way. Maybe the crew has to deal with different reactions from other pirates and people they encounter. Some might underestimate her because she's a girl, but Luffy's strong will remains the same, and she shows everyone that gender doesn't matter when it comes to being a great pirate.
Well, first of all, Luffy is a very emotional character. When he discovers Zoro's sacrifice, he would probably go into a state of shock initially. Then, his reaction could be explosive. He might not be able to accept it right away and would try to find a way to reverse the situation. He could also start blaming himself for not being there to protect Zoro, which would further fuel his determination to become stronger and protect the rest of his crew better in the future.
In addition to Luffy and Garp, other characters could also play important roles. For example, some of Luffy's crewmates like Zoro or Nami might be present when Luffy calls Garp. They could add their own perspectives and reactions. Also, there could be some marines around Garp when he receives the call, and their reactions to Garp's decision to go to Luffy could also be part of the story.
His personality would stay largely the same in terms of his goals and values. He still wants to be the Pirate King. But in social situations, he could be more cautious. As a girl, he might face different types of challenges when interacting with other pirates or people in general. He might have to rely more on his wits rather than just brute force in some situations, which could be a new aspect of his personality development in this fanfic.
One popular ace luffy garp fanfiction is 'The Bonds of Family'. It delves deep into the complex relationships between Ace, Luffy, and Garp. It shows how their different personalities interact and how their family bond influences their actions.
I don't have enough context to determine exactly who 'garp' is. It could be a newly created character by the fanfic writer, or it might be a character from a relatively unknown story that is being incorporated into the 'ace fanfic'.