Yang would likely be more laid - back about it initially. She might see it as an opportunity for Roman to turn his life around. However, if Roman showed any signs of reverting to his old ways, Yang would be quick to put him in his place. And Professor Ozpin would be very watchful. He would see Roman as a wild card and would be constantly evaluating whether his presence at Beacon is a benefit or a danger.
Ruby would probably be very suspicious at first. She knows Roman from his criminal activities and would find it hard to trust him right away. But being the kind - hearted person she is, she might give him a chance to prove himself.
Weiss would be extremely wary. Given her family's status and her own sense of propriety, she would see Roman as a threat to the integrity of Beacon. She might even try to get him expelled. Blake, on the other hand, having some experience with the seedy side of life, might be more understanding but still keep an eye on him.
Blake would likely be cautious. Given her past experiences, she doesn't trust easily. But she might also be interested in Harry's different perspective. Yang would be more open - minded, ready to welcome him as long as he doesn't pose a threat. The teachers, like Ozpin, would be more calculating. He'd want to figure out how Harry got there and what his intentions are.
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.
If Adam joined Beacon in fanfiction, it could lead to a lot of interesting plot developments. For one, his relationship with Blake could have a very different start. Instead of being an antagonist from the get - go, he might be a comrade at first. His combat skills would surely make him stand out during training sessions, and his views on the Faunus - human relations could stir up both positive and negative discussions among the students.
The other characters would be shocked. Weiss would probably be the first to try and figure out what's wrong with Ruby. Blake would be worried about Ruby losing her way, and Yang would be furious. Yang might even go on a solo mission to bring Ruby back, not fully trusting the rest of the team to handle it delicately. The rest of the characters like Jaune and Nora would also be in disbelief and would start planning ways to rescue Ruby.
Some might be amused. Naruto characters have their own set of stories and adventures, and seeing the different and often wild ideas in RWBY fanfiction could be a source of entertainment for them.
In 'rwby watches earth fanfiction', Ruby would be wide - eyed and eager to explore every new thing. She'd be constantly asking questions about how things work. Weiss would be shocked by the lack of a Dust - based power system but would soon start to admire Earth's ingenuity. Blake would be drawn to the underground subcultures on Earth, like punk or goth cultures. Yang would be amazed by the variety of fighting styles on Earth, from martial arts to boxing. They all would have to come to terms with the fact that Earth is a very different place from Remnant.
The characters in Fairy Tail would have a wide range of reactions. Makarov, as the guild master, would be very cautious. He would need to ensure that Acnologia's presence doesn't put the guild in more danger. Happy would be constantly on guard around Acnologia, ready to fly away at the first sign of trouble. The Thunder Legion would likely be in a state of high alert. However, some of the more adventurous members like Cana might see it as an opportunity for great adventures and powerful new magic. It would be a complex situation with different characters having different stances based on their personalities and past experiences.
Some of the more cautious members, like Erza, might be a bit wary at first. She would be concerned about how Igneel's presence might change the power dynamics within the guild and what his intentions truly are. But over time, as she sees his positive influence, she would likely warm up to him.
Yang would be completely heartbroken. She'd likely go through a period of intense grief and anger, possibly even blaming herself for not being able to protect Ruby. Weiss would be deeply affected too. She might become more reserved and solemn, vowing to use her skills to uphold Ruby's ideals. Blake would be inspired by Ruby's sacrifice to be more active in fighting against the darkness. She might see it as a call to arms to make Ruby's sacrifice not be in vain.
Weiss would probably be very protective at first. She has always had a bit of a mother - hen side to her, and seeing Ruby in a more vulnerable, deaged state would bring that out. She would likely try to keep Ruby out of trouble and make sure she was taking care of herself.