Well, there are also those characters who might be a bit shocked or confused. Take Levi from Attack on Titan. He's a very serious and no - nonsense type of character. If he were to read some of the fanfic about him that deviated too much from his own self - perception, like being made into a comical or overly emotional character in the fanfic, he might be taken aback at first. But then he might also realize it's just a different interpretation and not take it too seriously.
Well, it depends on the nature of the fanfiction. Some anime characters might be amused if the fanfiction is light - hearted and full of comical situations. For example, if it's a fanfic about a cooking competition among the characters from a shonen anime, they might react with good - natured laughter and competitiveness. They could also be confused if the fanfiction takes their story in a very strange or unexpected direction, like suddenly making a character from a historical anime end up in a space adventure.
For example, the following examples could be used to summon anime characters in novels like Random Summoning:
" Demonic Dao Patriarch " was a fantasy novel with the theme of cultivation and Dao. It described the grudges and conflicts between the various sects in the Jianghu. The protagonist of the story, Wei WuXian, was a gifted immortal cultivator. For some reason, he was exiled to the home of the Patriarch of Yiling to begin his new journey of cultivation. In this world, he had met many different people, including Wen Qing, Lan Lan Xian, and so on. They had experienced many challenges and tests in the process of cultivation, and had also produced many emotional entanglements.
Kakashi would be very observant. He would look for how the fanfiction writers understand the world of Naruto, the values and the moral lessons. He might even use some of the creative ideas from the fanfiction in his own teachings if he thought they were valuable and in line with the spirit of the original story.
There could be characters who are outraged. If the fanfiction distorts their personality or makes them do things completely against their nature, they may be very angry. For example, a noble character made to act like a coward in the fanfiction would likely not take it well.
They might be confused at first. RWBY has its own unique lore and concepts that are different from many anime. So anime characters may need time to understand things like Grimm and Huntsmen. For example, if Goku from Dragon Ball was watching, he'd probably be like 'What are these strange monsters?'.
They could be surprised. The fanfiction might show them in scenarios they never imagined, like a shy character being in a very bold and adventurous situation.
They could be angry. Consider a character like Ichigo from Bleach. If the fanfiction makes him look weak or changes his character in a way that goes against his core values, he would likely be furious. After all, he has his pride as a Soul Reaper and a protector.
A few might be angry. If the fanfiction shows them in a negative light or changes their backstory in a way they don't like, they could get really mad. For example, if a character with a noble past is made into a villain in the fanfiction, they'd be furious.
One great anime react fanfiction could be one where the characters from 'Naruto' react to modern technology. It's interesting to imagine how Naruto and his friends would be amazed by smartphones or the internet. Another could be characters from 'Attack on Titan' reacting to a world without Titans, exploring their newfound peace and how they adjust to normal life. There are also many 'My Hero Academia' react fanfictions, like the heroes reacting to different villain strategies from other universes.