He might become more assertive. Normally, Harry is somewhat hesitant at times, but as a gang leader, he'd have to be quick in making decisions. For example, when facing an enemy attack, he can't afford to be indecisive.
His sense of responsibility would expand greatly. While he already has a strong sense of responsibility in the original story, as a gang leader, he'd be responsible for the lives and actions of his gang members. He'd have to make sure they are trained well, fed, and protected. This could make him a bit more overbearing at times, but it would also strengthen his leadership skills. He'd also become more secretive as he'd need to protect the identities and operations of his gang from potential threats.
He might become more assertive and decisive. Normally, Percy is a bit of a reluctant hero, but as a gang leader, he'd have to make quick decisions to protect his gang. He could also become more secretive, as gang activities often need to be kept under wraps.
If Harry Potter were a Superman fan in fanfiction, his personality would likely take on a more optimistic and positive outlook. Superman represents hope and the best of humanity (even though he's not human). Harry, having faced so much darkness in his life, might latch onto this aspect of Superman. He would be more likely to see the good in people and situations. This could change his relationships, as he would be more forgiving and more likely to give people second chances. His new - found optimism could also inspire others around him, like his classmates at Hogwarts, to be more positive in their own lives.
He'd be much more somber. Dementors drain happiness, so he'd lack the cheerfulness that normal Harry has.
His personality would likely become more reserved and secretive. Growing up under Morgana, who is often associated with the shadows in legend, Harry would be less likely to trust easily. He might also be more calculating, always thinking several steps ahead like Morgana was known to do in her schemes.
He'd be more aggressive. Gangs often have a tough and sometimes violent culture, so Harry might be quicker to anger and use force.
Ino could be part of Naruto's gang. With her mind - control jutsu, she could be very useful for gathering information or infiltrating enemy groups. Shikamaru, with his high intelligence, would be like the gang's strategist. He could plan out all the gang's operations and anticipate the moves of their opponents. Then there's Kiba. His ability to communicate with Akamaru and his tracking skills would be beneficial for the gang, especially when they need to find someone or something.
He might become more reserved. Shinobi are often taught to keep their emotions in check, so Harry would be less likely to be as openly angry as he sometimes is in the original story.
His personality would be more aggressive. Yautja are hunters, and growing up with them, Harry would adopt their aggressive nature. He would be more direct in his actions and less likely to hesitate.
He would become more rebellious. Harry has always had a bit of a rebellious streak in the original series, but as a pirate, it would be amplified. He'd be more likely to question authority and do things his own way without waiting for permission.
If Harry Potter was raised by Natsu, his personality would change drastically. Natsu is a very passionate and hot - tempered character. Harry would be influenced by this passion and would be more driven in his pursuits. He would no longer be the meek boy who was bullied by the Dursleys at the start. Instead, he would be more confident and assertive. His sense of justice would also be more like Natsu's, which is more about immediate action rather than following a set of bureaucratic procedures. He would probably have a stronger sense of loyalty towards his friends as well, because Natsu values friendship above all else and would instill this value in Harry.