In some fanfiction, Maleficent could change her goals. Instead of just being a force of chaos, she might start to strive for power within the wizarding political system. This would require her to interact with the Ministry of Magic, Hogwarts faculty, and other important institutions in the Harry Potter world, completely changing her role from the original fairy - tale inspired character.
She can become more sympathetic. Sometimes in fanfiction, authors might give her a tragic past that makes her actions more understandable. For example, if she was wronged by the wizarding community in the past, it could justify her actions against them in the fanfiction.
Maleficent might gain new magical abilities in fanfiction. Since the Harry Potter world has a vast array of magic, she could learn spells like the Patronus charm or even develop her own unique spells that combine her fairy magic with wizarding magic. This would change her from just a dark force to a more complex magical being.
He would be more cunning. Maleficent is a master of manipulation, and Harry would likely pick up on those skills. He might be less naive compared to the original Harry.
He might become more in tune with nature. Since the Phoenix is a symbol of rebirth and nature in the wizarding world, Harry could develop a stronger sense of environmental magic. For example, he could be able to communicate with other magical creatures more easily, not just the Phoenix.
He becomes more humble. Elves are used to serving and being in a subservient position. Growing up with them, Harry would learn the value of every being, no matter their status. He'd be less likely to show off his magical abilities like he might have in the original story.
He becomes more brooding. The knowledge of necromancy and the power it brings can isolate him as he realizes it's a power not many understand or accept. So he might withdraw from his usual jovial self.
He might become more sneaky and calculating. Since he's a thief now, he would have to be good at hiding his actions and planning his 'heists'. His moral compass might also shift a bit as stealing isn't exactly an ethical behavior in the normal wizarding world.
The Potter Manor could make Harry more confident. Living in a grand and important family home might give him a stronger sense of identity. He would know that he comes from a long line of great wizards, and this could boost his self - assurance in his magical abilities.
His character becomes more confident. Since he was raised by a god, he has a certain level of self - assurance that normal Harry might not have. He may not be as easily intimidated by Voldemort or other threats.
His character becomes more independent. As the son of Artemis, he has a different kind of power and heritage that sets him apart from other wizards. This could lead to him relying less on the help of others and more on his own instincts and abilities. He might also be more secretive about his new powers, which adds a new layer of mystery to his character. For example, he could start to disappear at night to train in the moonlight without telling his friends.
In 'Harry Potter son of Loki' fanfiction, Harry changes significantly. His sense of identity is greatly shaken. He no longer just sees himself as a simple wizard. He now has this connection to Norse mythology. This makes him more curious about different forms of magic and otherworldly things. He may become more of an outcast as well, since his heritage is so different. But this also makes him stronger in some ways. He has to rely on himself more and develop his own unique set of skills and powers that come from both his Potter and Loki lineage.
Harry in this fanfiction is likely to be more ruthless. Voldemort's upbringing would make him less empathetic. He may value power above all else and be more willing to use dark magic to achieve his goals. His relationships would also be different. He wouldn't have the same close - knit group of friends as in the original story. Instead, he might be surrounded by Death Eaters or those who follow Voldemort's ideology.