Deku would be devastated. He has always seen Bakugo as both a rival and someone he deeply cares about. His reaction would likely be a mix of extreme grief and guilt. He might feel that he could have done more to protect Bakugo. Kirishima, who is Bakugo's friend, would be heartbroken. He would probably be filled with anger towards whatever caused Bakugo's death and would be determined to make the culprit pay. Ochaco and the other classmates would also be in shock. They would come together to support each other through the difficult time, but they would also feel a great sense of loss as Bakugo was an important part of their class dynamic.
Perhaps in the fanfic, Bakugo dies due to a tragic accident. For example, he could be involved in a training exercise that goes horribly wrong. His death would then shock the entire U.A. High School. His classmates would struggle to come to terms with it, and it might cause some of them to question the safety measures in place at the school. It could also be a turning point for the story, leading other characters to be more cautious and less reckless in their actions.
Nagisa would be completely devastated. She has a very deep connection with Tomoya, and his death would likely cause her to sink into a deep depression. She might even lose the will to live, especially if it happened suddenly. For example, if he died in an accident, she would be left with a sense of emptiness and longing for him.
Ruby would be deeply saddened. She might blame herself for not being able to protect Blake. Weiss would probably be in shock at first, then become more determined to fight against whatever caused Blake's death. Yang would be furious and seek revenge. She has a very close bond with Blake, and her death would likely fuel Yang's anger towards the enemy.
The other demigods would be devastated. Percy was like a leader to many of them. Annabeth, his girlfriend, would be heartbroken. She might go on a quest for revenge against whatever or whoever put Percy in the situation where he had to sacrifice himself. The campers at Camp Half - Blood would also be in mourning. They would probably hold a big memorial for Percy. His friends like Grover would be in shock and would feel a great sense of loss.
Hermione would likely be devastated. She might go into a deep state of mourning, but also use her intelligence to try and figure out what led to Harry's death. Ron would be angry and heartbroken at the same time. He'd probably want to seek revenge if there was someone or something responsible.
Edward would be completely shattered. He might lose all sense of purpose and even consider ending his own existence. Jacob would be filled with anger and grief. He might blame Edward and the Cullens for not protecting Bella. Charlie would be heartbroken and would likely be in a state of shock for a long time.
The other members of Team RWBY would be deeply affected. They would start to question their own abilities and the purpose of their fight. Some might withdraw into themselves, like a broken Weiss who shuts out the world for a while. Yang, on the other hand, could become reckless in her pursuit of vengeance, endangering herself and others. Blake would try to hold the team together, but she would also be mourning privately. The other friends and allies in the RWBY universe would also be in mourning. Qrow might blame himself for not being there to protect Ruby, and Ozpin would see it as a great setback in the fight against evil.
Shigaraki would likely be disgusted if the fanfic made him seem weak or less of a threat. He'd probably scratch at his neck in irritation. Dabi would be dismissive. He'd think fanfics are just a waste of time and not worthy of his attention. Toga, though, might be intrigued. If the fanfic had a lot of blood and gore in it, or if it focused on her relationships in an interesting way, she could be really into it.
Well, there would be a range of reactions. Some fans might be inspired by it. They could see it as a way to explore deeper themes of sacrifice and mortality within the Star Wars universe. They would start discussions about what Ahsoka's death means for the overall story and characters. However, a large number of fans would simply be heartbroken. Ahsoka has a huge fan following, and her death in a fanfic would shatter the dreams of many who hoped for a more positive future for her in fan - created stories.
The characters would be devastated. Grover, Percy's best friend, would be heartbroken. He might lose his ability to find Pan because of the emotional turmoil. His search for Pan was always connected to his friendship with Percy, and without Percy, he could be lost.