Well, first of all, Naruto's power of sensing chakra might be enhanced to sense ki as well. His shadow clone jutsu could potentially be combined with ki clones, creating a whole new level of clone - based attacks. His original wind - style jutsu could be infused with ki energy, giving them a different color and more potency. And instead of just using the Nine - Tailed Fox's chakra for power - ups, he could have some sort of transformation related to his Saiyan heritage from Goku Black. This would not only change his appearance but also boost his overall combat abilities far beyond what he could do in the original Naruto series.
His powers would likely be a blend of Kronos' and Rhea's. Kronos was associated with time, so Percy might have some control over time. He could slow it down or speed it up in a small area. Rhea was a mother goddess, so Percy might have a strong connection to nature and the ability to heal. This is different from his original powers as Poseidon's son where he mainly had control over water and could communicate with sea creatures.
He might have enhanced physical abilities. Black Widow is known for her strength, agility, and combat skills. Naruto could inherit these, making him an even more powerful ninja in close - range combat. For example, his punches and kicks could be more forceful.
Well, in the regular Naruto story, his power growth is based on training and his Uzumaki heritage. But as the son of Zeus, his power development could be more instantaneous. He might inherit some of Zeus' knowledge of magic and warfare. His Sage Mode could be combined with Zeus - like powers, making him a force to be reckoned with. For example, his Sage Mode chakra could be infused with Zeus - inspired lightning, creating a new and extremely powerful form.
His powers would be much more extreme. Instead of just controlling water like he does as a son of Poseidon, he could control light and air elements. His connection to Aether could give him the ability to manipulate the very fabric of the upper atmosphere. And from Hemera, he might have the power to bring instant daylight or even manipulate time related to the day - night cycle.
Fanfiction expands on the existing Naruto powers in unique ways. In the original, the Sharingan has specific abilities. But in fanfiction, it could be evolved to have additional powers such as the ability to predict not just an opponent's moves but also future events in general. Also, some fanfictions introduce hybrid powers that combine different ninja techniques from different clans. For example, a character might have a power that combines the Inuzuka clan's beast - like abilities with the Hyuga clan's gentle fist technique, which creates a completely new and exciting power dynamic that is not part of the original Naruto series.
His powers would likely be much more elemental. Since Ouranos is associated with the sky, he might have powers over the air, such as creating powerful winds or even controlling the weather on a greater scale than before. And from Gaea, he could have enhanced earth - based powers like causing massive earthquakes or having a deeper connection to the land, perhaps being able to communicate with all forms of plant and animal life that are rooted in the earth.
His powers would likely be more about destruction in a controlled and purposeful way. Instead of just fighting to win battles, he'd be able to use his energy to completely obliterate things at a much larger scale. For example, he could destroy entire star systems with a single blast if he needed to.
Naruto might also have some sort of mind - control or illusion - based powers. Jenova has been known to influence minds in some storylines, so Naruto could use this to his advantage in battles or to manipulate situations. For example, he could create illusions that are so realistic that his enemies can't tell the difference. This would be a great addition to his existing ninja skills.
His powers would likely be enhanced to a godlike level. For example, his Rasengan might be able to destroy entire landscapes with a single throw. His speed could be so great that he appears to teleport. His chakra reserves would be seemingly infinite, allowing him to spam powerful jutsus without getting tired.
In fanfic, Naruto's Rasengan could have additional abilities. Maybe it could split into multiple smaller Rasengans that can target different enemies simultaneously, while in the original it was mainly a single, concentrated attack.