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.
Well, in the 'Harry Potter as a Phoenix' fanfiction, Harry might change in terms of his leadership. The Phoenix is a very majestic and inspiring creature. So, Harry could take on a more confident and leading role among his peers. He could inspire others not just with his courage but also with the wisdom and power that the Phoenix imparts to him. Also, his understanding of magic could shift from a more practical and textbook - based approach to a more intuitive one, as he learns from the Phoenix's way of using magic.
The phoenix could give Harry a sense of purpose. Knowing he has such a powerful and magical creature by his side, he might feel more confident. For instance, he could be more daring in his adventures and face his enemies without as much fear.
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.
In this fanfiction, Harry's change is quite significant. Firstly, his view of himself and his place in the world is completely altered. Instead of just being a wizard, he is now part of something much bigger. This new identity gives him a different kind of courage. He's not just fighting for the wizarding world against Voldemort, but also has a connection to Asgard. His relationships with his friends also change. They might see him in a new light, and he might have to deal with their different reactions. He could become more of a leader, using his new powers and status to inspire others. And his magic might even be influenced by his Asgardian heritage, making it more powerful or having different manifestations.
In this kind of fanfiction, Harry often becomes more proficient in potions and other areas that Snape is good at. His relationship with Snape also makes him more empathetic towards Snape's past and the Slytherin house in general. He may not be as quick to judge people based on their house. Also, he might develop a more complex view of the wizarding world's politics, as Snape is deeply involved in some of the darker aspects of it.
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.
Well, in this fanfiction, Harry Potter is no longer the pure - hearted hero we grew up with. He becomes a character that challenges our pre - existing notions. His actions in destroying Hogwarts force us to re - evaluate his character traits. We might see him as more of a tragic figure, someone who was pushed to the edge and made a very controversial decision that had far - reaching consequences.
He might become more confident in his pure - blood heritage. Since Dorea Black is from an old pure - blood family, she could instill in Harry a sense of pride and belonging that he didn't have in the original story. This could change his attitude towards other pure - bloods and half - bloods.
In these fanfictions, Harry's character transformation is quite drastic. He loses his sense of morality. His loyalty, which was once towards his friends and the good side, now shifts to Voldemort. He becomes more power - hungry, willing to do whatever it takes to gain more power, including using dark magic without hesitation. He also becomes more secretive and manipulative, using his former relationships to further Voldemort's goals.
Harry in this fanfiction might be a lot more complex. His identity is no longer that of the Boy Who Lived in the traditional sense. He has to come to terms with the fact that his parents are two very different and controversial figures. He may become more of an outcast, even among his friends at Hogwarts. His sense of right and wrong could be more blurred, as he has the influence of Bellatrix's dark ways and Snape's own morally ambiguous actions. He might be constantly questioning his own nature and whether he is destined to follow a path of good or evil.