His core personality might stay the same. Naruto has always been determined and full of energy. So, even as a child, he would still be eager to prove himself. However, he might be a bit more naive again, like he was in his early days. He would still have that strong sense of justice but might not be as tactful as his older self.
His personality might become more innocent. Without the weight of his usual responsibilities and power, he could be more curious and open - minded. For example, he might be more willing to explore new things instead of being so focused on winning and power as he usually is.
His core personality might not change much. He'd still be brave and protective. But he might be more in touch with his emotions, as society often allows women to be more openly emotional. He could also be more perceptive about the subtleties in relationships.
His personality might become more brooding and mysterious. Vampires are often associated with being deep thinkers and having a certain allure. JK might be more withdrawn as he tries to hide his new nature from others.
His personality might become more curious, like a cat. He could be more easily distracted by shiny things or new scents. Also, he might become a bit more independent, as cats tend to be, but still hold onto his strong sense of justice and protectiveness for his friends.
Well, in his cat form, Pitch Black could become more territorial. He might hiss at other animals or people who come too close to his 'domain'. His once menacing presence could be translated into a more stealthy and watchful nature. He would still be cunning, but now he would use his cat - like abilities to his advantage, like sneaking up on things. And perhaps his patience would increase, as cats are known to wait for the perfect moment to pounce.
They might become more withdrawn. Since vampires are often associated with secrecy, the maknae could start to keep their thoughts and feelings to themselves more. For example, they may not share their newfound struggles with bloodlust with their friends right away.
Naruto's core personality might not change much. He'd still be the determined and enthusiastic ninja. However, as a girl, she might become a bit more sensitive to others' feelings. For example, she could be more empathetic towards Sakura's insecurities. Also, she might be more cautious in some situations, as society in the ninja world might have different expectations of girls. But overall, she'd still have that Naruto - like spirit of never giving up.
His personality might become more cautious. Since he has a greater responsibility as a guardian, he can't be as reckless as he was sometimes in the original Naruto series.
His personality might become more refined. Since the Yamanaka are a bit more sophisticated in their ways compared to Naruto's original upbringing. He could be more calculating and less impulsive, as he'd be influenced by the family's focus on mental prowess.
If Naruto were an Anbu captain, he'd likely be more reserved. He'd have to keep his emotions in check, which is different from his usual open - hearted self. He might not be as quick to jump into action without thinking, as the Anbu operate more stealthily.