Some Transformers could be indifferent. They might see fanfiction as something that has little to do with their real missions and existence. Bumblebee is a popular character, but not all Transformers would care about the stories made up about him in fanfiction. They are more focused on their own tasks and the overall well - being of their kind.
Shinji would probably be terrified at first. He's already hesitant and scared in his normal battles, and Godzilla is much larger and more intimidating than the Angels he usually faces. Asuka would likely be more aggressive, thinking she can take on Godzilla with her Eva. Rei, on the other hand, would be very calm and observant, trying to understand Godzilla's nature. Misato would be in a panic initially, but then quickly start strategizing on how to deal with this new threat. Gendo would see Godzilla as either a new opportunity or a major obstacle depending on his long - term plans.
Harry would probably be cautious at first. He's used to strange things in his world, but these giant mechanical beings would be quite different. Hermione would be curious and start asking a million questions about how they work. Ron might be a bit more fearful, especially if the Transformers made loud noises. But overall, they would likely be intrigued and see if they could be allies against any potential threats.
In general, the Evangelion mangas are considered good. They expand on the anime's universe, providing more depth and character development. However, it depends on personal preferences as some might find the style or pacing not to their liking.