His personality would likely become more erratic. The Joker's influence is all about chaos and anarchy. Harry might start to laugh at inappropriate times and find pleasure in causing trouble just like the Joker. He could lose his sense of empathy as he is constantly exposed to the Joker's cruel and inhumane behavior.
His personality might become more traditional in some ways. Since the founders are from an earlier time, their values could rub off on him. He might be more reserved like some of the older wizards.
His personality would likely become more conflicted. He has a good heart, but being around Bellatrix would make him question a lot of things. He might become more withdrawn as he tries to hide his true self from Bellatrix.
His personality would likely become more self - assured. Growing up with the founders, he'd be constantly exposed to great magic and wisdom, which would boost his confidence. He might also be more independent as he'd be trained in a more solitary way by the founders.
He might become more stoic. Gibbs' influence could make Harry hold his emotions in check more. Instead of being so impulsive sometimes, he'd think before acting.
If adopted by the Malfoys, Harry's personality would be a complex mix. He would be exposed to the Malfoy's elitist views from a young age. This could make him initially seem cold and distant. However, his innate goodness would still be there. He might struggle to reconcile his true self with the Malfoy persona he's expected to have. For example, he might be polite and proper in public as a Malfoy, but secretly help those who are oppressed by the pure - blood ideology, showing that his original kind - hearted personality is still fighting to surface.
His personality might become more confident, even a bit arrogant. Growing up in a rich family, he would be used to getting what he wants. For example, he might not be as humble as he was in the original story.
Percy's personality could become more adaptable. The Avengers operate in a different world compared to where Percy is from. He'd have to learn new ways of doing things. So, he might become more flexible in his thinking and actions. Also, he could become more serious in some ways, as the Avengers often deal with high - stakes situations.
If adopted by Jiraiya, Naruto would probably be more self - assured. Jiraiya would instill in him a sense of pride in his abilities. He'd also be more of a free spirit. Jiraiya's influence would mean Naruto would be more likely to take risks and explore new things without as much hesitation as in the original story. He might also be a bit more flirty, as Jiraiya has his own charm when it comes to the opposite sex.
His personality would likely become more complex. On one hand, he still has his maniacal side. But on the other, he now has a new focus. He could be more protective, like a wild animal protecting its young. He might also show moments of vulnerability, which is very different from his usual confident and unpredictable self. He could start to question his actions and how they would affect his daughter's view of him.
His personality could also develop in new ways. Since the RWBY world has different social structures and challenges, Naruto could become more diplomatic. He'd have to interact with different races and factions, like the Faunus. So, he might learn to be more understanding and empathetic towards those with different backgrounds, which could add new layers to his already complex personality.