Voldemort would still be a major enemy. But with Kratos raising Harry, Voldemort might face a much more challenging opponent. Also, any dark wizards or creatures that oppose Harry would be in trouble. Kratos wouldn't tolerate any threats to Harry, so even the Death Eaters would have to be extra careful. Another potential enemy could be those in the wizarding world who oppose Kratos' methods of raising Harry, seeing them as too brutal or un - wizard - like.
In this fanfiction, Voldemort and his Death Eaters are obvious enemies. However, there could be other foes. The Ministry of Magic might become an enemy if they see Harry as being too influenced by Kratos' violent ways. Kratos himself has a long list of enemies from his own mythology - based storylines. There could be some sort of crossover where those enemies target Harry because of his connection to Kratos. For instance, if there are any Greek mythological creatures or gods who oppose Kratos, they might try to harm Harry as a way to get back at Kratos.
Imagine 'Harry Potter Raised by Kratos'. Harry would grow up in a very different environment. Kratos has seen and been through a great deal of pain and struggle. He would pass on his survival instincts to Harry. Instead of the rather sheltered life at Hogwarts in the original story, Harry might be trained in the harshest of conditions. His magic could be combined with Kratos' combat knowledge. For example, he could use spells to enhance his physical attacks, much like how Kratos uses his magic items in his games. This fanfiction could rewrite the entire concept of Harry's character development, making him more of a warrior - wizard hybrid.
Some of the dark wizards who are looking for a new source of power might target Harry. They might think that by capturing or controlling him, they can access the powers of Trigon. There could also be entities in other dimensions that see Harry as a key to opening portals between worlds and want to use him for their own malicious purposes.
Alien races that are envious of the Earth - born magic could be enemies. They might see Harry and the wizards as a threat to their own power and dominance in the universe. Also, there could be dark wizards who have escaped to space to avoid the law on Earth and continue their evil deeds, now with a new set of space - related challenges and opportunities.
Voldemort or his remaining Death Eaters could be the main enemies. They would see Harry's new blade master abilities as a threat. Another potential enemy could be a dark wizard from a foreign land who is jealous of Harry's power.
Obviously, Harry Potter himself. Then there could be a Texan version of Hagrid, like a big - hearted rancher who discovers Harry's magical abilities. There might also be a local witch or wizard who acts as a mentor, someone with a thick Texan accent. And don't forget about the muggles in Texas, Harry's classmates at a regular school before he goes to Hogwarts. They could be curious, tough - as - nails Texans who don't quite understand Harry's strange behavior at times.
Some of the Death Eaters who might have survived or changed their ways in an alternate universe could be the slashers. They would bring their knowledge of the Dark Arts and their own twisted view of the wizarding world. Bellatrix Lestrange, if she had a different path, could be a very interesting slasher figure in such a fanfiction, as she is extremely powerful and unpredictable.
Obviously, Harry himself. Then there could be German - born wizards and witches who become his friends or mentors. There might be a strict German potions master like Snape in Hogwarts. And perhaps a German - version of Dumbledore, an old and wise wizard who guides Harry.
Well, aside from Voldemort, there might be corrupt elements within the assassin organization that raised Harry. They could see his magic as a threat to their power and secrecy. Also, there could be some dark wizards who team up with the assassin enemies of Harry. These villains would be more complex as they combine the danger of dark magic with the stealth and combat skills of assassins. And there could be a new character, perhaps an assassin who was once a friend but turns bad due to jealousy or a thirst for power, creating a more personal and dangerous threat to Harry.
In such a fanfiction, apart from Harry, there could be a gang of street urchins. One of them might be a girl who has a special connection with Harry. And then there are the professors at Hogwarts. Snape would probably have an even more difficult time with this street - raised Harry. He might see him as a troublemaker at first. And Dumbledore would be the one trying to guide Harry in this new, different situation, still seeing his potential.
The Death Eaters could still be a major threat. Even with Voldemort gone, some of them might be trying to revive the dark ways and see the wizard king as a big obstacle in their path.