The most emotional moment would probably be when Banner actually makes the decision to sacrifice himself. It's a moment of self - lessness that goes against our natural instinct for self - preservation. Just imagining him looking around at his friends, knowing he's about to give up his life for the greater good. His face might show a mix of fear and determination. It's a moment that would bring tears to the eyes of the readers as they realize the depth of his sacrifice.
In the movie, his sacrifice was more of a physical fight - related one. But in a fanfic, it could be more of an emotional or mental sacrifice. For example, he could sacrifice his own sanity to power up a device that saves everyone. He might go into a state of eternal madness while his friends watch helplessly, which is very different from the movie's more action - based sacrifice.
Well, it could be that Naruto sacrifices himself to seal away a dark and ancient curse that is threatening to destroy not only the ninja world but all of existence. He realizes that his unique connection to the tailed beasts and his strong willpower make him the only one who can perform this self - sacrificing sealing jutsu. So, he says his goodbyes to his friends, family, and the village he loves and gives up his life to save everyone.
Perhaps it's when Percy actually makes the sacrifice. He stands there, facing whatever danger it is, and as he gives himself up, there's a moment of complete silence. His body might start to glow or something, signifying his life force being given away, and his friends can only watch in horror.
In the fanfic, it could be that Fleur is in a situation where she has to perform a dangerous task to save the wizarding world, like going into an ancient and deadly magical place. Harry, realizing the importance of her mission and also having deep feelings for her (maybe a secret love), sacrifices his own safety by going with her and ultimately giving his life to ensure she can complete the task and save everyone.
In a 'Stop all the clocks' Harry Potter fanfic, perhaps the most emotional moment could be when a beloved character sacrifices themselves. For example, if a character like Lupin, who has already faced so much hardship, gives up his life to protect Harry and his friends. This would be heart - wrenching as Lupin has a family, a son, and so many friends who care about him. His death would not only be a loss for the characters in the story but also for the readers who have grown to love him throughout the series.
It could be a long - lost Uchiha with powers beyond that of Madara. This Uchiha could have been in hiding, gathering power and knowledge, and his ultimate goal is to reshape the world in his own dark image. Naruto realizes that the only way to stop him is by sacrificing himself.
One possibility is that Percy sacrifices himself to save his friends and Camp Half - Blood from a powerful, unbeatable enemy like an ancient primordial god. He might use his powers to create a shield or diversion that allows everyone else to escape while he faces certain death.
I'm sorry I can't directly recommend a specific 'Percy sacrifices himself for Artemis' fanfic. But you can try searching on fanfic platforms like Archive of Our Own (AO3). There are tons of fanfics there, and by using relevant keywords in the search bar, you might be able to find one that suits your interest.
The immediate impact would likely be chaos. Criminals would feel emboldened, thinking that there's no one to stop them. The police force would be under a great deal of stress as they try to fill the void left by Batman. However, Batman's sacrifice could also inspire new heroes to rise up. People who were inspired by his selfless act might take it upon themselves to protect the city in their own ways.
Perhaps in the fanfic, there is a prophecy that states only a hero's ultimate sacrifice can save Artemis from a dark curse. Percy, being the selfless hero he is, decides it has to be him. He goes through a series of trials first, trying to find an alternative way but in the end, he has no choice. He sacrifices his life force to break the curse on Artemis. This act not only frees Artemis but also has far - reaching consequences in the Percy Jackson universe, like changing the power dynamics between the gods and demigods.