Some characters might be really engaged and find it interesting. They could relate to the story or the characters in the fanfiction.
Characters' responses could vary widely. Some might be emotionally moved, while others might focus on the writing style or the creativity of the fanfiction author.
Some characters might be amused. They could find the creative interpretations in the fanfiction interesting, especially if it gives a new spin on their relationships or adventures in the Batman universe.
Some might be amused. For example, characters like Nagito Komaeda could find the different interpretations of himself in fanfiction either interesting or in line with his self - deprecating view. He might chuckle at how fans perceive his luck cycle in strange new ways.
They could also be offended. If the fanfiction portrays them in a way that goes against their values or character traits in the original work, they may feel misrepresented. For example, if a character is always shown as noble in the original but is made into a villain in the fanfiction. They might not like this change at all and feel insulted.
They might be amused. Since fanfiction often contains creative and sometimes humorous takes on the original story, characters could find it funny to see how fans imagine different scenarios for them.
They could also be confused. If the fanfiction takes a really wild turn from the original story, characters might not understand the new concepts or relationships presented. For example, if a fanfiction pairs two characters who have no interaction in the original in a romantic way, it could be bewildering for them.
They may also be confused. Fanfictions often take the original story in new directions, and characters might not understand why certain things are written the way they are. For example, if a fanfiction changes the relationship dynamics between characters, they could be left scratching their heads.
They might be amused. Some characters could find the creative interpretations in the fanfiction quite interesting and it might make them laugh or at least bring a smile to their faces.
Characters might have a range of reactions. Some could be dismissive if the fanfiction doesn't match their idea of the Tarzan universe. However, others might be completely engrossed. They could be so into it that they start to think about how the events in the fanfiction could have happened in the 'real' Tarzan world. They may also have emotional responses, like feeling sad for a character's misfortune in the fanfiction or happy when something positive occurs.
If it's characters like Rhodey, he might be a bit critical. He knows Tony so well in real life, so he might nitpick the inaccuracies in the fanfiction. But at the same time, he could also enjoy seeing new and exciting storylines that still capture the essence of Iron Man.
Well, some characters might be amused. They could find the creative interpretations in the fanfiction quite interesting and might even laugh at the funny or unexpected scenarios. For example, Toothless from HTTYD might be curious about how he is portrayed in the fanfictions.