Well, perhaps a major plot twist could be that the CCG (Commission of Counter Ghoul), which is supposed to be against ghouls, has been secretly working with some ghouls for their own ulterior motives. This would be a huge shock as it goes against everything they are known for. Also, there could be a twist where a ghoul's kagune (their weapon - like organ) mutates in a way that gives them an unexpected advantage or disadvantage.
In this Tokyo Ghoul fanfiction about watching the future, a really cool plot twist might be that the future shows that the world is actually on the verge of a total collapse due to the ongoing war between ghouls and humans. However, there is a prophecy that a half - ghoul, half - human will emerge and be the key to saving the world. But the identity of this being is completely unknown, and everyone is searching for it, creating a whole new level of intrigue and mystery.
One of the most compelling new characters could be a young ghoul with a unique kagune ability. Maybe it's a kagune that can change forms in ways that no other ghoul has seen before. This would make them stand out and be a force to be reckoned with in the story.
Perhaps a plot twist where the Mist from Percy Jackson's world starts to affect Tokyo Ghoul. The Mist could make humans in Tokyo see ghouls as something completely different, like mythical creatures from their own Japanese folklore. This would not only change how the humans in Tokyo Ghoul react to ghouls, but also how the ghouls themselves perceive their place in the world and their relationship with humans.
One of the most interesting plot twists could be that Naruto discovers a new form of chakra that has the power to rewrite history. This would completely change the power dynamics in the Naruto universe.
Well, for a Tokyo Ghoul fan, reading fanfiction while being a fan of the original can be a mixed bag. On one hand, it's exciting to see how other fans' creativity expands the world. For example, there could be fanfictions that focus on the backstories of minor characters. However, sometimes the quality can vary. Some might not capture the essence of the Tokyo Ghoul world as well as others. But overall, it gives a chance to delve deeper into the fandom.
One interesting plot twist could be the ghouls in the Attack on Titan world. Imagine if ghouls were hidden among the titans. They could feed on the bodies of dead titans or even on the soldiers without being detected at first. Another could be the Ackermans having some sort of connection to the ghoul powers. Maybe their enhanced strength is related to a dormant ghoul gene. And a third could be the Scouts finding a way to use ghouls' kagune to fight the titans more effectively, like creating weapons out of kagune material.
One interesting plot twist could be a character from 'Supernatural' getting the kagune power from 'Tokyo Ghoul'. For example, Dean suddenly having a rinkaku kagune and having to learn how to control it while still hunting demons. It would add a whole new layer to his character as he struggles with this new, inhuman power.
In some crossovers, like the one with 'Bleach', a really creative plot twist is when Kaneki's kagune somehow gets linked to a Hollow's power. It completely changes the power dynamics and makes for some intense battles. The idea that his ghoul nature could be combined with Hollow abilities in such a way was unexpected and exciting.
Well, one of the most interesting plot twists could be a character that was thought to be on the side of the humans actually being a secret agent for the Titans all along. This would completely change the dynamic of the story and the relationships between the characters.
Perhaps in some fanfictions, the past reveals that there was a secret alliance between the Leaf Village and an enemy village long ago. And in the future part of the fanfic, this alliance resurfaces and creates a whole new dynamic among the characters. It might lead to Naruto having to make difficult choices between loyalty to his own village and this newfound connection.
A cool plot twist could be a ghoul - Titan hybrid. Imagine a Titan with the regenerative abilities of a ghoul. This would pose a whole new level of threat to the characters from both universes. Also, the idea of the ghouls' coffee being a valuable resource in the Attack on Titan world could be an interesting twist. Since coffee is so important to ghouls, it could have some unforeseen effects on the Titans or the people in that world.