It could be that the assassin was initially a victim of some dark wizard's experiment. Harry, being the hero he is, feels responsible for the child and decides to raise him. In the process of raising, he unknowingly nurtures the assassin-like qualities in the child because of the unique circumstances and challenges they face together.
One challenge could be controlling the assassin's violent tendencies. Since the person is being groomed to be an assassin, it's likely they have a natural inclination towards violence, and Harry has to find a way to temper that while also teaching self - defense.
Well, his story would be extremely different. For one, he'd be trained in stealth and combat skills from a young age instead of learning magic at Hogwarts in the traditional way. He might not have the same group of friends as in the original story. Instead of having Ron and Hermione as his closest allies, he could be more solitary or have assassin - type comrades. His view of good and evil would also be more blurred as an assassin, perhaps seeing the world in terms of targets and those who hire him rather than the clear - cut good vs. evil of the wizarding world. And his relationship with Voldemort would be more of a hit - or - miss rather than the epic battle of good against evil.
No. The idea of Harry Potter being involved in such a situation goes against the values of the original series. The Harry Potter series is mainly about magic, friendship, and fighting against evil. This kind of fanfic concept not only distorts the characters but also involves inappropriate and unethical content.
Maybe it's a character who has a hidden identity. It could be someone who was thought to be dead but actually survived and is now seeking revenge. This person could have a grudge against Moody for something that happened in the past. Or it could be a new character created specifically for the fanfic, a dark wizard from a far - off land who has been hired to kill Moody.
Most likely very negatively. The Harry Potter fan community values the positive aspects of the series. They would see this fanfic as a disrespect to the original work and its characters.
He'd be more disciplined. His character would be shaped by military values. He'd be less likely to act impulsively and more likely to think things through strategically.
Harry's character would be more attuned to the deeper magics. He would be less likely to jump into things without thinking. Since Flamel is a master of alchemy, Harry might be more interested in the scientific aspects of magic. He would also have a greater respect for life and magic's power, as Flamel, with his long life, would instill in Harry a sense of wonder and caution about the forces they deal with.
Obviously, Harry Potter himself. Then there could be some Canadian - born witches and wizards as his friends. Maybe a tough - as - nails girl from the Yukon who is an expert at ice magic. And a laid - back boy from Vancouver who has a special talent for communicating with magical forest animals.