The worlds of Naruto and Hellsing are very different. Naruto is set in a more traditional ninja - based world with different clans and jutsu. Hellsing is a dark, gothic world full of vampires and ghouls. In fanfiction, an interesting plot could be a group of Naruto ninjas being sent to the Hellsing world to stop a powerful vampire from taking over the ninja world. They would have to adapt to the new rules and powers there.
Immortality in Naruto - Hellsing fanfiction can bring a whole new level of storytelling. In Naruto, some characters are effectively immortal through means like the tailed beasts' chakra. In Hellsing, vampires are immortal. Combining these, a story could be about a character trying to find a way to end the immortality curse. Maybe Naruto uses his sage mode to understand the nature of vampiric immortality in Hellsing.
One possible crossover in Naruto and Hellsing fanfiction could be the sharing of powers. For example, Naruto's ability to use chakra could be combined with the vampiric powers in Hellsing. Maybe a character from Naruto gets turned into a vampire and has to deal with the new powers and the moral implications in the Hellsing universe.
One way this could be developed is by having Naruto's abilities misused or corrupted in the Hellsing universe. Maybe some dark magic or experiment twists his chakra into a force that creates 'monsters'. For example, his shadow clone jutsu could be warped so that the clones turn into uncontrollable, monstrous entities. Another aspect could be his connection to the Nine - Tails. If the Hellsing organization were to try and harness the power of the Nine - Tails, it could go horribly wrong and lead to the creation of new and terrifying monsters.
It could be an interesting but very challenging concept. The magic in Harry Potter is quite different from the dark, vampiric elements in Hellsing. However, if a writer were to take on this as a fanfiction, they could potentially create some really unique scenarios. For example, imagine Harry having to face off against Alucard from Hellsing in a battle of magic vs. dark powers. But overall, it's a concept that would require a lot of creativity to pull off successfully.
Well, it might be that in the fanfiction, Naruto's immortality is a result of a powerful experiment gone right. He then has to deal with living in a modern society where his values as a ninja sometimes clash with the modern way of life. For example, he might struggle with the concept of modern warfare versus his traditional ninja combat. His immortality also means he has to watch friends and loved ones age and die while he remains unchanged, which can be a source of great emotional turmoil.
One common theme is the clash of different power systems. In Naruto, there are chakra and ninja techniques, while in Hellsing, there are vampires and powerful weapons. Fanfictions often explore how these different power systems interact when the two worlds meet.
One idea could be a crossover where Naruto is somehow transported to the Hellsing universe and meets Seras. Maybe Naruto's unique powers, like his shadow clones, could be used in battles against the vampires in the Hellsing world. Seras, with her vampire abilities, might initially be seen as an enemy to Naruto but they could end up teaming up.
One interesting Naruto Hellsing werewolf fanfiction could be where Naruto has werewolf - like powers in the Hellsing universe. For example, a story might explore how Naruto's tenacity and his newfound werewolf abilities interact with the dark and vampire - filled world of Hellsing. Maybe he teams up with Alucard to fight a common enemy.
Well, in a Young Justice fanfiction, the concept of Naruto being immortal could be integrated in various ways. One way could be through some sort of magical or scientific experiment gone wrong that gives him immortality. Maybe it's a meta - human experiment in the Young Justice universe that accidentally gives Naruto the same powers as Vandal Savage, including immortality. Another possibility is that it could be a result of a powerful jutsu he uses that has unforeseen consequences and makes him immortal.
He'd bring a new sense of hope. The Hellsing organization is often mired in dark and violent affairs. Naruto's positive attitude could be a breath of fresh air for the members. For example, Seras might be inspired by Naruto's determination to protect those he cares about.
One common theme is power. Since 'godlike' is in the title, often the characters gain extraordinary powers that are a blend of Naruto's ninja abilities and Hellsing's dark, supernatural elements. For example, a character might have Naruto's chakra control along with Alucard - like immortality from Hellsing.