I'm not entirely sure as I haven't read that specific 'bad fanfic'. But generally, a 'bad fanfic' might have issues like poor characterizations, inconsistent plotlines, or bad grammar. Maybe in this 'ben 10 omniverse' fanfic, the author doesn't understand the original lore well and messes up the powers of the characters or creates really out - of - character relationships.
To improve it, one should focus on character development. In Ben 10 Omniverse, each character has a distinct personality. So, make sure the characters in the fanfic act in ways that are true to their original selves. Also, improve the writing style. Use proper grammar and vary the sentence structure to make it more interesting to read. And don't forget to check for plot holes and fill them in.
One possible plot could be that Rook and Ben go on an adventure to a new planet in the Ben 10 Omniverse. They encounter a strange alien species that has a unique power. Ben tries to use his Omnitrix to transform into an appropriate alien to deal with the situation, but there are some glitches. Rook, with his Plumber skills, helps Ben figure out what's wrong and together they overcome the challenges and make new friends among the aliens.
I'm not sure specifically as there could be many interpretations. It might be a fan - made story related to 'Ben 10' that goes in a really bad or off - track direction. Maybe it has a plot that completely distorts the original characters or storylines of 'Ben 10'.
One possible fanfiction could be about Ben and Kai going on a new adventure in the Omniverse. Maybe they discover a new alien species that is causing chaos in a far - flung galaxy. Ben uses his Omnitrix to transform into different aliens to try and stop the threat, while Kai uses her martial arts skills to fight alongside him.
I haven't actually read this specific fanfic, but generally in a 'Ben x Esther' fanfic in the Ben 10 Omniverse setting, it might explore their relationship in different ways. It could involve adventures where they team up, and their characters' growth while dealing with various threats in the Omniverse. Maybe it also delves into how their different personalities interact and complement each other.
One possible plot could be that Esther gets caught up in an alien conspiracy in the Omniverse. Ben, being the hero, steps in to save her. As they work together to uncover the truth behind the conspiracy, they start to fall for each other.
Adventure is likely to be a theme as well. The Ben 10 Omniverse is full of exciting places and situations. Fanfics may center around Attwa and Ben Lemon going on adventures, using their unique abilities or powers to overcome obstacles.
Well, in a 'Ben 10 Omniverse Ben x Kai' fanfic, perhaps it could start with Kai joining Ben on one of his inter - dimensional adventures. Along the way, they encounter various challenges that test their relationship. Ben might use his Omnitrix in creative ways to protect Kai, and in the process, they realize their mutual attraction. For example, when they are trapped in a strange alien world, Ben has to transform into different aliens to find a way out while also keeping Kai safe from the local dangers.
An interesting aspect could be exploring Rook's past more deeply. Maybe he has some secrets from his time before being a Plumber that are related to the Ben 10 Omniverse. Ben could help him uncover these secrets while they are on a mission. For example, they could be investigating an ancient alien artifact, and as they dig deeper, Rook's past starts to unfold.
In Ben 10 Omniverse fanfics, the relationship between Ben and Gwen can be really interesting. Usually, they have a very strong bond as cousins. In some fanfics, their relationship might be explored more deeply, like how they support each other during battles. Ben with his Omnitrix powers and Gwen with her magic often make a great team, and fanfics can show their interactions in new and exciting ways, such as when they face a new and extremely powerful enemy that they have to combine their skills to defeat.