Aside from the champions, it's very possible that Harry's friends, Hermione Granger and Ron Weasley, play important roles. They often support Harry in his adventures and would likely be involved in this story about the third task. There might also be other Hogwarts students or professors who are important in the fanfic, like Dumbledore who always has a guiding presence in such events, or Snape who might be involved in some way related to the task, perhaps in providing potions or other magical aids.
Most likely the main characters would be the Triwizard Tournament champions. So, it could be Cedric Diggory, Fleur Delacour, Viktor Krum, and of course, Harry Potter.
It could also feature some original characters created by the fanfic author. These new characters might be students who have a special connection to the third task, either through a family connection to the Triwizard Tournament or some other unique backstory. They could add new layers of drama and interaction to the story of the third task at Hogwarts.
Look to Chapter 168 for the clearest answer. It begins with Su Yinwan spoke those words with a pitiable expression, then lowered her..., keeps building through The next second, a crisp notification sound rang in her Divine Sense,..., and lands on The Gu Family had strict family education;
The best chapter pointer here is Chapter 166, "Daniu Gets Jealous!". It opens with Only after everyone in the small courtyard had left, did Zhao Lang stride... and closes on However, after interviewing the villagers, no one has gone missing, so we....
Chapter 166 is the strongest chapter-level answer because it starts from Only after everyone in the small courtyard had left, did Zhao Lang stride... and follows through on However, after interviewing the villagers, no one has gone missing, so we....
The best chapter pointer here is Chapter 170, "This Family Will Fall Apart Without Jiang Li". It opens with Watching the two who had long remained silent, the PD shifted his position... and closes on [Didn't the other guests also do farm work in the rain all morning, isn't....
Chapter 159 is the strongest chapter-level answer because it starts from Seeing the red light of the camera turn on, Su Yinwan looked at the... and follows through on Shang Shaobai, who was browsing through files, received a call from his....
Look to Chapter 121 for the clearest answer. It begins with Seeing that Wen Jiaojiao's condition had improved significantly, Director..., keeps building through A doctor, donned in a white coat, hurriedly got out and immediately asked..., and lands on You're supposed to be a man who conquers.
Chapter 158 is the strongest chapter-level answer because it starts from Reluctantly, Jiang Yan had no choice but to forcibly join the group for... and follows through on we're just very close friends." Sister Li had a vast number of followers....
Chapter 127 is the strongest chapter-level answer because it starts from Witnessing Jiang Li leave with a bucket, Jiang Yan refused to admit... and follows through on He Yun, who chose the codonopsis, became the one with the most challenging....
If you want the clearest chapter reference, go to Chapter 126. Early on, Wen Jiaojiao initially wanted to cause trouble.; later, the chapter leans on But when her gaze swept around and landed on Jiang Li, who was standing at....
Chapter 185 is the strongest chapter-level answer because it starts from He was so anxious that he immediately picked up the megaphone. and follows through on The next, she'd complain that the ground was too slippery to walk on..