Well, it could be a story where Naruto, being the son of Khal Drogo, might inherit some of his father's leadership skills and warrior spirit. Maybe he would use his ninja abilities along with the boldness from his supposed father to face new and greater threats in the Naruto universe. He could also form unique alliances with characters from both the Naruto world and the world of Khal Drogo, creating a whole new dynamic of power and relationships.
Perhaps the plot could involve Naruto growing up in a different cultural setting due to his relation to Khal Drogo. This could lead to him having a different perspective on things like honor, family, and combat. He might introduce some of the ways of Khal Drogo's people into the Hidden Leaf Village, or vice versa. And of course, there would be a lot of action as Naruto tries to prove himself worthy of his heritage, both as a ninja and as the son of a great leader.
Obviously, Naruto would be one of the main characters. Since he is the son of Khal Drogo in this fanfic, he would be central to the story. Another potential main character could be Sasuke. His relationship with Naruto could be even more complex now, as Naruto has this new and strange heritage. And maybe one of Khal Drogo's most trusted warriors could also be a main character, coming to the Naruto world to help Naruto understand his father's side of the family and teach him things about his newfound heritage.
Another possibility is that there is some sort of magical or otherworldly influence. Perhaps an evil force manipulates Naruto into believing that Drogo is a danger to his world or loved ones. So, Naruto, being the hero he is, takes it upon himself to eliminate the perceived threat. However, this would go against Naruto's usual nature of trying to understand his opponents first, so it would be an interesting twist in the fanfiction.
In a fanfic where Khal Drogo is killed, it could lead to a whole new set of alliances. Daenerys, in her grief, might be forced to make unexpected partnerships. For example, she could turn to some of the smaller, more oppressed kingdoms that were previously afraid of the Dothraki. This could change the entire power dynamic in the fictional world. Additionally, the cultural aspects of the Dothraki could be explored further as they deal with the loss of their leader. Their traditions and how they adapt or break away from them in the face of such a huge loss would be an interesting aspect to explore in the fanfic.
One idea could be a fanfic that focuses on Khal Drogo's early life before he became a powerful khal. It could explore his upbringing, the challenges he faced, and how he came to lead his khalasar. Another idea is a fanfic where Khal Drogo has to deal with a mysterious illness that starts to affect his strength and leadership. This could show a different, more vulnerable side of him. A third idea could be a story about Khal Drogo's relationship with his horse. It could be a story told from the horse's perspective, showing how they bonded and what their adventures were like together.
One common theme is the clash of cultures. Bella comes from a very different world than Khal Drogo, and exploring how they interact and adapt to each other's cultures is often a central part of these fanfics. For instance, Bella might be shocked by some of the more brutal aspects of Drogo's culture, while Drogo could be intrigued by Bella's more 'civilized' ways.
Daenerys is an obvious choice. Their relationship in the original series was complex and passionate, and in fanfiction, there are so many ways to explore it further. Another good character could be Ser Jorah Mormont. His loyalty to Daenerys and his knowledge of Westeros could create interesting dynamics with Khal Drogo. And perhaps the witch Mirri Maz Duur could also be paired with him in a fanfiction that delves into the more magical and vengeful aspects of the story, exploring what could have happened if their interactions had taken a different turn.
On a more personal level, Naruto himself might have to deal with the guilt. Despite being in a different world and situation, Naruto has a strong moral compass. Killing Drogo, even if it was in self - defense or due to a misunderstanding, could haunt him. He might question his actions and his role as a hero, which could lead to an internal struggle and character development within the fanfiction.
One idea could be that Khal Drogo travels to the future and is amazed by modern technology. He might see skyscrapers and cars and think they are strange magic. He could try to adapt to this new world while still holding onto his warrior ways.
I think Missandei could be an interesting character to pair with Khal Drogo in a fanfic. She is intelligent and has a strong sense of self. Her presence could bring out different sides of Khal Drogo as he interacts with someone who has a very different background from his own. Also, Ser Barristan Selmy could be paired with him. Selmy's experience and honor could clash or blend with Khal Drogo's more savage and wild nature, creating a dynamic and engaging story. And then there's Grey Worm. His stoicism and military discipline could contrast with Khal Drogo's leadership style, leading to some really interesting character - development scenarios in a fanfic.
The unique aspect is the clash of two very different universes. Harry Potter's world is full of magic spells, wands, and magical creatures, while Khal Drogo comes from a more primitive and warrior - based culture. In fanfics, this can lead to interesting exchanges of ideas and skills.