A common power in fanfiction is enhanced magical senses. Characters can sense magic from far away, like being able to detect a hidden magical artifact from miles away just by the faint magical aura it emits. This helps in treasure - hunting type of storylines.
Harry might gain the ability to dodge attacks more easily. Sans has a certain 'instinct' for avoiding harm, and if Harry had this, it would be much harder for his enemies to land a hit on him. This would be really useful in duels, especially against powerful dark wizards. It could also make his Quidditch playing even more amazing as he could dodge bludgers effortlessly.
Immortal Naruto would bring his superhuman strength and speed, which are results of his ninja training. In the wizarding world, this would make him a force to be reckoned with. His Sage Mode, if he could access it, would give him enhanced senses and more powerful attacks. He could also bring his never - give - up attitude. This would inspire the characters in the Harry Potter world, especially in times of despair. His ability to use chakra to run up walls and across water could also be used in interesting ways in the wizarding world, like during a chase or escape situation.
He could have enhanced physical abilities like Black Widow. So, he'd be super agile, able to jump from high places and land safely, and have great reflexes. Also, he might be a master of disguise, which would be really useful in the wizarding world. He could blend in with different magical creatures or people to gather information.
In some fanfictions, Harry Potter might absorb abilities through magical artifacts. For example, he could find a special amulet that transfers the powers of the previous owners to him when he touches it.
Fanfiction often explores the combination of powers in ways not seen in the original. In the books, each type of magic seems to be somewhat separate. However, in fanfiction, a character might be able to blend potion - making skills with combat magic. So, they could create potions that enhance their spell - casting abilities during a duel, which is a concept not really in the main series.
He might have enhanced control over the Hogwarts wards. Since he is the heir, he could be able to manipulate the protective spells around the school more easily than others.
One cool power often seen in such fanfiction is teleportation. This allows characters to quickly move from one place to another, escaping danger or arriving at crucial moments just in time. There are also powers related to healing, where a character has an extraordinary ability to cure any injury or illness, which can be very useful in the often - dangerous wizarding world.
His powers would be really interesting. He could use his magic to enhance the technology he inherits from Stark. For instance, he could make his Iron Man suit invisible using a disillusionment charm. He'd also have an edge in combat as he could use both magic and technology. His spell - casting ability could be used to hack into computer systems or disable enemy technology. And his knowledge of the wizarding world would give him an advantage in dealing with threats that are both magical and technological in nature.
In this fanfiction concept, Harry's magic has its own advantages. His ability to apparate could be a huge advantage in the Naruto world, allowing him to quickly move from one place to another, something that is not as easily done with ninja techniques. But on the other hand, the Sharingan in Naruto can copy and predict movements, which could pose a challenge to Harry. His magic like the Patronus charm is a powerful defensive and offensive tool that doesn't really have an equivalent in the Naruto world in terms of its nature.