One possible plot line could be that Harry is drawn to the veil against his will. As he gets closer, he starts to feel a strange pull and then suddenly he and the veil become one. After that, he can see the spirits of the dead clearly and they communicate with him, guiding him to some hidden knowledge or power.
In this kind of fanfiction, it might explore the idea of Harry having a very deep and perhaps spiritual connection with the veil. It could be about him transcending some kind of boundary or becoming part of the mystery that the veil represents in the Harry Potter universe. Maybe it's about him gaining new powers or knowledge through this union with the veil.
One possible plot line could be that Harry Potter is magically transported to Minato's world and has to learn ninja techniques to get back. Along the way, he combines his magic with Minato's skills and becomes a unique force. Another could be that Minato's spirit somehow enters Harry's body, and Harry has to deal with new memories and abilities while still facing the challenges in his own world.
One possible plot line could be that Fem Harry Potter has dreams about Enkidu. These dreams inspire her to seek out more information about him. She then discovers a hidden library in Hogwarts that contains books about ancient Mesopotamian mythology. As she reads more about Enkidu, she starts to develop new spells based on his powers.
Perhaps there is a prophecy in both worlds that involves a 'veil' and a'metamorphmagus'. A group of characters from both Harry Potter and Naruto universes have to come together to figure out what the prophecy means. The metamorphmagus ability could be key in unlocking the secrets of the veil. For example, the shape - shifting might be required to enter a hidden realm behind the veil. Along the way, they face challenges from both worlds, like dark wizards in the Harry Potter world and rogue ninjas in the Naruto world, and they have to use their combined skills and abilities to overcome these obstacles.
Well, he might accidentally bring some of the dark forces from his world to Remnant. Or, on the other hand, he could bring new hope and ideas to fight the existing threats in Remnant. His presence could also cause some political unrest as the different factions in Remnant might try to use him for their own gains. And of course, his own journey of self - discovery would be completely different in this new world.
One interesting plot line could be Harry using his seer abilities to foresee the return of Voldemort much earlier and being able to prepare better defenses. For example, he might see the specific plans of the Death Eaters and be able to stop them before they even start. Another could be that he sees the true nature of some of his so - called friends who might be secretly working for the dark side. This would add a whole new layer of drama and mystery to the story.
Maybe Naruto would face a powerful enemy that he can't defeat with his normal jutsu. So, he decides to take on the Batman - like approach of using strategy and gadgets. He could build his own ninja - style gadgets and use them to outwit his foe. This would be a major shift in his usual fighting style.
A common plot might involve Grindelwald taking Harry away from the Dursleys much earlier than in the original story. He could introduce Harry to a different side of the wizarding world, filled with ancient and dangerous magic. Harry would then have to decide whether to embrace Grindelwald's vision or fight against it, all while dealing with his own identity and the power he possesses.
One possible plot line could be Snape discovers a new side of Harry during a difficult potions experiment. Harry shows unexpected creativity, which makes Snape re - evaluate his long - held grudges.
In some 'Harry Potter is a pilot' fanfictions, there could be a plot where Harry has to transport magical creatures by air. He'd have to figure out how to keep them calm and safe during the flight. Also, perhaps he teams up with other wizard pilots to form a sort of magical air force to protect the wizarding world from threats in the air.