Perhaps a major plot twist could be that the values instilled in Harry by the Nathrezeim are not as dark as everyone expects. He might bring a new perspective to the wizarding world, one that challenges the traditional view of good and evil. For example, he could show that there are shades of grey in magic and relationships, and that not all associated with the Nathrezeim are purely evil.
With Dumbledore, it would be a complex relationship. Dumbledore would be cautious yet intrigued by Harry. He would want to guide Harry away from the potentially dark path that his Nathrezeim upbringing could lead him to. Harry, on the other hand, might be resentful of Dumbledore's interference at first.
In many Harry Potter fanfictions, the concept of being 'raised by darkness' can take various forms. It might involve a character being brought up in an environment influenced by dark magic or dark wizards. For example, a character could be raised in a family that secretly practices the Dark Arts. This could lead to the character having a different moral compass compared to those raised in the light. They may struggle with the line between right and wrong, as their upbringing has exposed them to unethical magical practices.
In this fanfiction, Harry's development could be centered around his understanding of family. Growing up with a scorpion, he has a very different concept of what a family is. This could lead to him having a complex relationship with the Weasleys or other surrogate families in the wizarding world. He might be hesitant to accept their love and care at first, but gradually come to realize the value of a real family. Also, his magical development could be more instinctive, like how a scorpion reacts instinctively to threats, Harry might use magic in a more impulsive yet effective way when in danger.
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.
Harry would likely develop a very different personality. He may be more solemn and less prone to the typical teenage angst that the original Harry had. Since he is raised by Death, he might be more in tune with the darker aspects of life and magic from a young age.
Harry would probably be more attuned to dark magic. His upbringing by Satan would expose him to different forms of magic and he would have a different understanding of power. He might be more ruthless in achieving his goals and less concerned about the consequences for others. For example, in the original series, Harry was always worried about the safety of his friends, but in this fanfiction, he might use his friends as pawns if it served his purpose.
Perhaps it could be Thor from Norse mythology. Thor is the god of thunder. So, Harry could have the power to control lightning or storms. He would be a very formidable wizard with such powers. His Hogwarts years would be full of situations where he uses these thunder - related powers to solve problems or fight off enemies.
Gabriel could be an original character created by the fanfiction writer. Maybe he's a powerful and reclusive wizard who lives on the outskirts of the wizarding world.