Well, it could be that Naruto discovers his divine heritage as the son of Jupiter. Maybe he has new powers like controlling lightning in a more god - like way. He could also have to face enemies from the Roman pantheon who are jealous of his unique status.
Well, it could start with Harry having some strange powers or dreams that lead him to discover his true father is Jupiter. Then he might have to navigate between the wizarding world and the realm of the Roman gods. Maybe he'd use some of Jupiter's powers in his battles against Voldemort.
One possible antagonist could be a jealous Roman god who doesn't want Naruto, as the son of Jupiter, to gain too much power. Maybe Pluto, who might see Naruto as a threat to his own domain in the afterlife.
It could work if Jupiter had some connection to the chakra system in Naruto's world. For instance, Jupiter's power could be the origin of a very powerful and rare type of chakra. Naruto, being his son in this fanfiction, would have a natural affinity for this special chakra, allowing him to perform feats that no other ninja could. This would change the power dynamics in the Naruto universe significantly.
One possible plot could be that Jupiter and Caine are in a relationship and the unexpected pregnancy throws their lives into chaos. They have to deal with the reactions of their friends and family, and also figure out how they are going to support a new life together.
Another possible new ability is the power of astral projection. Jupiter has a connection to the celestial realm. Naruto, as his son, could project his spirit into the astral plane. This would give him the ability to gather information from afar, spy on enemies, or even communicate with other celestial beings. It would add a whole new dimension to his ninja skills, making him not just a physical fighter but also a spiritual one.
One possible plot could be that Mars and Jupiter are on a secret mission in the Pokémon world. They might be searching for a rare Pokémon that has special powers which could help Team Galactic achieve their grand goals. They encounter various trainers and Pokémon along the way, and have to use their own Pokémon's skills to overcome obstacles.
One plot idea could be that Jupiter and Caine are in a dangerous situation. They think they might not make it out alive, and in a moment of intense emotion, they share a kiss. It could be a way to express their unspoken feelings for each other before facing the unknown.
Well, it could be about Ash traveling to Mars and Jupiter in the Pokemon world. Maybe he discovers new Pokemon species there. For example, there could be ice - type Pokemon on Jupiter because of its cold environment and fire - type Pokemon on Mars due to its hot nature. Ash could have to adapt his battle strategies to these new Pokemon and their unique abilities.
In a 'naruto son of bellatrix fanfiction', perhaps Naruto has some of Bellatrix's wild and unpredictable nature. He could be on a journey to discover his true identity and how he came to be Bellatrix's son. This might lead him to explore the secrets of the wizarding world and his own ninja abilities in a new light.
Well, one possibility could be that Naruto inherits some of Gilgamesh's arrogance along with his power. Maybe he has a special ability to summon ancient Babylonian weapons. And he could use this in his battles in the Naruto world, like against the Akatsuki.