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.
Luffy from One Piece would be an obvious choice. Their relationship in the original One Piece story is already complex and full of potential for more exploration in a crossover fanfiction. They could team up in a different universe or be forced to fight against each other in a strange new setting.
One popular type of OC is a female pirate who is as strong - willed as Katakuri. She challenges him in a battle of wits and strength, and their interactions create a lot of tension and intrigue in the fanfiction. For example, she might try to steal a precious treasure that Katakuri is guarding.
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.
For the quadruplets, their development could be based on their different relationships with the oven. One might be more cautious, another more adventurous in exploring its powers. Interaction with the OC would also shape them. If the OC has a different view on the oven's use, it can cause internal conflicts and growth among the quadruplets.
First, give each of the quadruplets a distinct personality trait. For instance, one could be the brave and impulsive one, always ready to jump into action. Another could be the calm and calculating one, thinking things through. You can also base their physical appearances on Katakuri but with some unique twists. For their backstories, think about how growing up in the world of One Piece affected them differently. Maybe one had a close encounter with a powerful enemy as a child that shaped their fear or determination.