Servants are also often main characters. For instance, Saber, with her noble and powerful presence. In the fanfic, she might have different relationships with other characters compared to the original. Her backstory and her connection to the Grail War are important elements that make her a main character.
The relationships between the characters can also be an interesting concept. In the fanfic, characters who may not have interacted much in the original could form strong alliances or rivalries. It can show how different personalities clash or complement each other in unexpected ways.
The Emiya ending in the Fourth Grail War fanfiction often shows his complex character. He is a hero with a strong sense of justice. In this ending, he might face difficult choices. Maybe he sacrifices himself to save others, which is in line with his selfless nature.
In fanfiction, Shirou could be exposed to a different moral code during the 4th Grail War. Maybe he meets a group of mages who have a more flexible view on right and wrong. This exposure could make him question his own beliefs and lead to a significant change in his character as he tries to find his place in this new moral landscape.
Another plot could involve Shirou getting a glimpse into the past of the Grail War through some sort of magical artifact. He discovers secrets that were long buried and this knowledge could either help him in the war or put him in greater danger as others may want to silence him.
If Naruto is summoned in the Holy Grail War fanfic, he would bring his unique ninja skills. His shadow clone jutsu could be used to confuse opponents and gather information. Also, his Rasengan could be a powerful offensive move against other Servants. He might have a hard time understanding the rules at first, but his determination would make him adapt quickly.
One key element is Emiya's determination. His unwavering will to do what's right is a big part of the ending. He won't be swayed by the temptations of the Grail. Another element is his relationships. His connection with other characters, like how he helps or is helped by them, can greatly affect the ending.
Another approach might be through a diplomatic solution within the fanfic. If the Masters were to realize the futility and destruction of the Grail War, they could come together and decide to end it. This would likely involve complex character development and plot twists, such as a shared enemy or a greater good that they all come to recognize.
One ethical reason is the amount of innocent bystander harm. In a Grail War, the battles often take place in populated areas, endangering ordinary people. Stopping the war would prevent this needless endangerment.
Well, perhaps in this fanfic, Emiya has to face some moral dilemmas during the fourth war. He might be forced to make choices between saving civilians and achieving his goals in the war. Also, his relationship with his Master could be explored in a new light. What if his Master has a hidden agenda that conflicts with Emiya's own sense of justice? That would surely add a lot of drama to the story.