His backstory could be explored in more depth. We could see more details about his time after winning the Hunger Games and how it led to his state in the 75th Hunger Games. Maybe he had some untold experiences that made him more cynical or more determined, which would be different from what we know in the original series.
Haymitch's skills could be enhanced or presented in a new light. In fanfiction, he could have some hidden talents or abilities that were not fully shown in the original. For instance, he might be an even better strategist than we thought, or he could have some unique survival skills that he uses to his advantage during the 75th Hunger Games.
By exploring his past traumas. His time in the Hunger Games must have left deep scars, and delving into those could show how they shape his present actions and decisions. For example, his alcoholism could be linked to the nightmares he has from the Games.
Haymitch is often characterized as a broken man in fanfiction. He has been through the Hunger Games as a victor and has seen the worst of it. He is usually depicted as cynical, sarcastic, and relying on alcohol to numb his pain. For example, he might make snide remarks about the Capitol's games. Effie, on the other hand, is characterized as proper and prim. She is very much into the Capitol's etiquette and appearance. She's always dressed up and concerned about presenting things in an orderly and proper way.
Haymitch might start off as the typical cynical and jaded character we know from the original Hunger Games. But as the 50th Hunger Games progress, he could gradually develop a sense of hope. Maybe he meets a young tribute who reminds him of his own past self and he decides to mentor them more earnestly. This could lead to him becoming more selfless and brave.
She might be developed to be more of a rebel. In the original, she was quite innocent. But in fanfiction, she could take on a bolder role, maybe secretly training to fight against the Capitol.
In some fanfictions, Prim's character might be developed as more assertive than in the original story. Instead of being the innocent, sheltered girl, she becomes a strategic thinker. For example, she could be the one coming up with plans to outwit the other tributes.
In fanfiction, Effie's personality can be more complex than in the movies. She might be shown as having deeper insecurities about her role in the Capitol's cruel system. For example, she could be secretly questioning the Hunger Games while still having to put on a show. Haymitch, on the other hand, might be portrayed as more openly emotional. In the movies, he often hides his feelings behind alcohol, but in fanfiction he could be more likely to express his anger, sadness, or even love more directly towards Effie.
One possible storyline could be Haymitch's internal struggle during the games. He might be haunted by his past experiences in the Hunger Games and be forced to relive some of his traumas. Another could be his strategic planning, how he uses his wits to outmaneuver the other tributes. Maybe he forms an unexpected alliance with a younger tribute and teaches them the ropes of survival.
In some fanfictions, Johanna's loyalty to her friends, especially Haymitch, is made into a central part of her personality. She is shown as being extremely protective of him, which is a bit different from the books where their relationship was more complex. Haymitch in fanfiction may be more proactive in trying to change the system. In the original, he was more resigned to the Capitol's rule until Katniss came along. Here, he could be constantly looking for ways to undermine the Capitol, and Johanna could be his partner in this endeavor.
Well, a plot twist could be that Haymitch is secretly in love with a Capitol citizen who is somehow involved in the Hunger Games. This would create a lot of internal conflict for him as he has to fight in the games while also dealing with his feelings for someone on the other side. Also, it could be that Haymitch's family has a hidden past related to the Capitol that is revealed during the 50th Hunger Games. This could put him in a difficult position as it might change the way the other tributes and the Capitol view him.
Well, in the original story, their relationship was mostly professional with a bit of underlying tension. In fanfiction, it could develop into a deep friendship right from the start. Maybe Effie starts to understand Haymitch's pain more quickly and they bond over their shared desire to protect the tributes. They could become confidants, sharing secrets about their pasts and fears.