Definitely the other ninja characters like Lloyd, Kai, and Jay. Their different personalities and powers would add depth to the story. Also, the villains from the Hands of Time series could be included to create conflict. For example, Acronix and Krux could be constantly trying to stop the sister from achieving her goals.
The 'Hands of Time' plot should be incorporated. Maybe Nya has a special connection to the time - related elements in the story. She could be the one to figure out how to stop the time - related threats or unlock secrets related to the 'Hands of Time'.
A fanfiction could focus on Nya's backstory as the sister in this context. It could show her growing up, her training, and how she came to be an important part of the ninja group during the 'Hands of Time' events. She might have had secret training sessions or a mentor that helped her become the strong character she is in the story. This could add depth to her character and the overall fanfiction.
Kai is often a popular choice. His connection to the story through his family ties makes him an interesting character to explore further. Also, his hot - headed nature can lead to some great character - development moments in fanfiction.
One idea could be exploring the sister's backstory in more detail. Maybe she had a special training or a hidden power that was only known to a few. Another could be a story where she gets separated from the main group and has to find her way back while facing her own personal demons.
The ninja themselves are always interesting. Their unique powers and personalities add a lot to the story. Kai with his fire - based abilities could have some really flashy moments in the Dragon Games. Lloyd, being the Green Ninja, would be a central figure. Also, the dragons are characters in their own right. Each dragon has its own distinct look and abilities. For example, the Ultra Dragon would be a powerful and majestic addition to the fanfiction.
Hermione would be a great character to include. She could be like an older sister figure to Harry's little sister, helping her with her studies and giving her advice on how to handle the challenges at Hogwarts.
One idea could be exploring the backstories of the characters from the Hands of Time arc in more detail. For example, the relationship between Kai and Nya's parents before they disappeared. Another could be a time - travel adventure where the ninja go back further in time than in the original story to prevent an even greater threat.
There could also be a character who is not directly related to the original ninja but has a special connection to the elemental powers. Maybe a young girl who discovers she has an ability to control an element that was previously thought to be lost. She would bring a fresh perspective to the group of the next generation and have to prove herself to the others.
Definitely her best friend. They could be there for her through all the mood swings, give her advice, and go shopping for baby stuff with her. Her parents, if they are part of the story's universe, would also be important. They could provide financial and emotional support. And if there's a love interest, he should be in it too, showing his care and concern, or maybe even having some doubts that they need to work through.
Hermione Granger from 'Harry Potter' could be an interesting addition. She could use her magic knowledge to study the mummy. Maybe she could find a spell to control or at least understand the mummy better. It would be a really unique combination of magic and ancient Egyptian mystery.