Well, Naruto might gain some super - powered abilities that are unique to the fanfiction world. Maybe he could control all the elements at once without any training.
Obviously, Naruto himself is the central character. His friends like Sakura and Kakashi are likely to be involved too. They might support Naruto in his new adventures or face challenges alongside him.
Well, in such a fanfiction, perhaps Jack discovers an ancient relic that bestows upon him the power of a Prime. He then has to learn to control this newfound power while facing off against old enemies of the Autobots. Maybe he teams up with Optimus Prime and the others, using his unique human perspective to come up with strategies that the Autobots hadn't considered before.
The Decepticons would obviously be the main antagonists. Megatron would see Jack as a new threat and would try to eliminate him. Starscream might also be jealous of Jack's new status and try to undermine him in any way he can.
One possibility could be that Naruto is drawn to boxing because of its physicality and the determination it requires. He might see it as a new way to test his strength and endurance outside of ninja battles. Maybe he starts training with a local boxing coach who sees his potential and helps him develop his skills.
In such a fanfiction, Naruto could be fascinated by Optimus Prime's technology. He might try to find ways to incorporate some of the Autobot's tech into his ninja tools. Maybe he'd develop a new type of shuriken that has some of the functions of Optimus' weapons. Also, Naruto could learn about the concept of a team from Optimus, where every member has a role to play, and apply it to his own ninja team dynamics.
One possibility is that Naruto, with his determination, could adapt Zeref's powers in a unique way. Maybe he'd use Zeref - like magic to enhance his ninjutsu. For example, he could infuse Zeref's death - based magic into his Rasengan, creating a more powerful and dangerous attack. Another aspect could be Naruto's personality change. If he becomes influenced by Zeref, he might become more brooding and less of the cheerful ninja we know. However, his core values of friendship and protecting the village would still likely be there, just warped a bit by Zeref's dark nature.
One possibility could be that Naruto is transported to the Mortal Kombat universe and through some magical or technological means, he takes on the powers and identity of Sub - Zero. Maybe he has to adapt to the new combat styles and the brutal nature of the Mortal Kombat world while still retaining some of his Naruto - like traits such as his determination and never - give - up attitude.
In the 'Naruto Becomes Super with IQ 500' fanfiction, Naruto's newfound intelligence could lead to him making amazing scientific breakthroughs in the ninja world. He could understand the chakra system on a whole new level and develop new jutsus that are far more powerful and efficient. His IQ would also help him in diplomatic situations, allowing him to negotiate better treaties and alliances for the Hidden Leaf Village. This would change the power dynamics not only in his village but across the entire ninja world.
Perhaps there is a portal that opens up between the Naruto universe and the Transformer universe. Naruto gets sucked into the Transformer world and has to adapt quickly. He finds that his Ninja training gives him an edge in this new world. He teams up with some Autobots, and they are amazed by his ability to move stealthily and use his chakra in unique ways. Together, they fight against the Decepticons who are planning to invade the Ninja world.