Tam is a character with a lot of mystery. He and his sister Linh are interesting, but Tam often gets overshadowed by Linh's more obvious power. Fanfiction could explore his inner thoughts and his past more. For example, a story about his time before he joined Sophie's group and what made him the way he is. And then there's Keefe's mom. She's only briefly mentioned, but she could be a really interesting character to focus on in fanfiction. Maybe she has her own secrets and plans that could change the whole dynamic of the Lost Cities if they were revealed.
I think Wylie could be one. He has so much potential but often gets overshadowed by the main characters. In fan fiction, his relationship with other characters, like his family ties, could be explored more, and he could be given his own adventures that showcase his unique skills and personality.
The chef on the expedition team. He seems like a really interesting character who could have a whole backstory about why he joined the dangerous mission. Maybe he was looking for some rare ingredients that were said to be in Atlantis. Another underrated character is the big, strong guy on the team. He could be the focus of a fanfiction where he has a secret soft side and forms an unexpected bond with an Atlantean child.
Sophie Foster is one of the main characters. She's the girl with special abilities.
Fitz is an interesting character. He is very intelligent and has a great sense of loyalty towards his friends. His relationship with Sophie also adds depth to his character. Keefe is also quite fascinating. He has a bit of a rebel streak and his sense of humor makes him stand out.
Keefe is also involved. He is quite mischievous and his texts might be full of humor or his wild ideas. He could text Sophie to pull her into one of his crazy plans or just to cheer her up when she's down.
I'm not positive, but I'd assume the keeper is a main character. There might also be some sort of mentor figure or a sidekick that helps the keeper in their journey related to the lost cities' legacy.
In the 'Keeper of the Lost Cities Tam Short Story', Tam is the key character. His sister Linh is likely to be a significant character as well, given their strong bond. Sophie Foster, a main character in the overall series, may also play a role. She has had various interactions with Tam in the past. And there could be other elves who are either friends or foes of Tam, like Dex, who might be involved in some way in the events of the short story, depending on the plot and the connections within the 'Keeper of the Lost Cities' universe.
Sophie would definitely be one of the main characters. Since she's at the center of a lot of things in the 'Keeper of the Lost Cities' series, she'd be actively texting to keep in touch with her friends and allies. Fitz is also likely, as he's often involved in the important events and is close to Sophie. Keefe too, as he's a bit of a wild card and his texts could be full of his usual antics and important information at the same time.
There may also be some antagonists or characters that create obstacles for Tam. These characters add conflict to the story, which makes it more interesting as Tam has to overcome the challenges they present.
The Wasp. She is a powerful and intelligent character. A fanfiction could center around her leadership skills within the Avengers. Maybe she has to lead the team in a situation where all the big - name heroes are incapacitated. It would show her strategic thinking and her ability to inspire others.