Definitely Kakashi. He's already very intelligent and has a wide range of skills. Time control could be an addition to his arsenal, and he could use it in creative ways in battle or for teaching purposes. Also, Madara Uchiha could be a likely character. He was always seeking more power, and time control would be a very powerful ability for him to have in fanfiction.
Melisandre is a likely candidate. She already has some mysterious powers in the original series, so in fanfiction, it's easy to imagine her delving deeper into mind control. She could use it to sway Stannis Baratheon more effectively or even target his enemies.
Superhero characters also make their way into time control fanfiction. Take Doctor Strange for example. His magical abilities already deal with otherworldly concepts, and time control can be added to his repertoire easily. He can use his powers to manipulate time to save the world or solve personal issues within the fanfiction.
I'm not entirely sure, but Naruto himself might be one of the main characters. Given his central role in the Naruto series, it's likely he'd be involved in any story related to time control in that universe.
One unique application could be that he uses it to relive his training days and improve his skills even more. He can go back to his time with Jiraiya and learn from his mistakes during training. Another is that he can slow down time during a battle to dodge attacks that are otherwise too fast for him.
In this fanfiction, Naruto's time - control ability would be a game - changer for the plot. He could potentially travel to different points in time to gather knowledge and power. Maybe he'd go back to the time of the Sage of Six Paths to learn some ancient and powerful jutsu directly. This new - found knowledge and power would not only make him stronger but also shift the power balance in the Naruto universe. It could lead to new alliances and enmities as other characters react to his new abilities, and thus completely rewrite the plot in many unexpected ways.
Naruto himself is often very popular. Fans like to write about him exploring the concept of chaos control, perhaps using it to become an even more powerful ninja. His positive attitude and determination can be interesting to explore in the context of this new power.
Sasuke would be a likely character to interact with Naruto as a Time Lord. Their complex relationship in the original Naruto series would add an extra layer of drama in a time - traveling scenario. Another could be Kakashi. His wisdom and experience would make for interesting conversations with Naruto, especially when Naruto has the power of a Time Lord. And of course, Jiraiya. Given his close relationship with Naruto and his own adventurous spirit, he'd be very involved in Naruto's time - traveling adventures.
Sasuke could also be a character who breaks the time loop. He is highly intelligent and has a thirst for power and knowledge. If he realizes that he is in a time loop, he would likely be very intrigued and start investigating. His Sharingan might give him some insights into the nature of the loop and help him find a way to break it.
Naruto himself is very likely to be central. Since he is the main character in the original series, any alteration of time would likely still revolve around him in some way. His journey and how it's affected by the time changes would be a major focus. Sasuke is also a prime candidate. His relationship with Naruto and his own quest for power and revenge could be greatly altered by time changes. Another one could be Kakashi. He has a lot of backstory and knowledge, and in an altered time, his role as a mentor or a ninja in general could be very different.
In Naruto fanfiction, time control can be used in various ways. For example, a character could use time - control jutsu to go back in time and prevent a tragic event from happening in the Naruto world, like the Uchiha massacre. They might also use it to speed up their own training, spending what seems like months of intense practice in just a few minutes of real - time.