Maybe through some kind of special training or a unique ritual. It could be that he discovers a hidden method within the ancient scrolls of his village.
In a Naruto - Superman powers fanfic, perhaps Naruto gets some of Superman's powers accidentally. He struggles to control the new powers like heat vision and super speed along with his own ninja abilities. Superman, on the other hand, discovers he can use chakra in a limited way and they both have to figure out how to use these new combinations of powers effectively.
In some Naruto fanfictions, Naruto's chaos powers might be shown as a wild and unpredictable energy source. It could make his jutsu more erratic but extremely powerful. For example, his Rasengan might become a chaotic, swirling mass of energy that can break through even the strongest defenses with ease.
Well, in some fanfics, Naruto's death could be like a sacrifice that unlocks some hidden or ancient power. Maybe his death releases a special chakra that was locked within him, and this chakra then transforms into new, more powerful abilities. It could also be that his death is part of a prophecy, and upon his death, a deity or some other powerful entity grants him powers as a reward for his selfless act of sacrificing himself.
Naruto's character development would likely be a wild ride. Bill Cipher's powers are extremely powerful and otherworldly. Naruto could start to see the world in a different light. He may become more detached from the normal ninja way as he explores the limits of his new powers. This could lead to some conflicts with his friends, as they might not understand the new Naruto who has these strange and dangerous powers. He might also gain a new sense of arrogance at first, thinking he can solve all problems with his newfound abilities, but then have to learn humility through some tough experiences.
Naruto's chakra - based powers would contrast with the ki - based powers of the Z Fighters. His Rasengan, which is a concentrated form of chakra, could potentially be combined with the energy blasts of the Z Fighters. For example, Goku could add his ki to Naruto's Rasengan to create an even more powerful attack. Also, Naruto's ability to transform, like his Nine - Tails Chakra Mode, would give him an edge in terms of raw power and speed, which could be on par with some of the Super Saiyan forms of the Z Fighters.
The 'godlike' powers could be integrated as an evolution of Naruto's existing chakra powers. Maybe he discovers a new form of chakra that gives him 'godlike' abilities like the ability to create or destroy matter at will. The 'flash' powers could be added to his movement skills, like he can move at super - speed by channeling this new form of chakra.
Well, Naruto's powers are mainly centered around his chakra control and the unique jutsus he has learned. In High School DxD, the powers are often related to sacred gears or devil abilities. If Naruto were to enter this world, his chakra might be seen as a new type of energy source. His ability to summon toads could be a huge advantage in certain situations. For instance, if he were in a fight against a powerful devil, he could summon Gamabunta, who could cause chaos and distraction. On the other hand, the devils' powers of illusion and teleportation could pose new challenges to Naruto, forcing him to adapt his combat style. His Rasenshuriken, which is a highly destructive jutsu, might be able to break through some of the stronger defenses in the DxD world.
She might have the ability to use the Rasengan in a new way, like infusing it with Byakugan - enhanced chakra control. This would make it more powerful and precise.