There are also those where Levi is genderbent. In these fanfics, the usually stoic and strong Levi in a female form can bring a whole new set of character traits. Maybe she's more in touch with her emotions in some interpretations, or she has different ways of leading the Survey Corps. It's all about seeing the familiar character in a new light.
One popular 'attack on titan fanfic' is 'The Titan's Heart'. It explores an alternate relationship between Eren and Mikasa. Another is 'Beyond the Walls', which delves into what could have happened if the characters had made different choices early on. And 'A Titan's Redemption' is also well - liked as it gives a new perspective on a Titan character.
I'm not sure specifically which 'attack on titan tickle fanfic' stories are the most popular. Fanfic popularity can vary a great deal. Some might gain popularity within certain fan communities on websites like Archive of Our Own or FanFiction.net. You'd probably have to search those platforms and look at things like the number of views, bookmarks, and comments to find the more popular ones.
One common theme could be alternate universe scenarios where the characters' genders are changed in a unique way related to the futa concept. For example, in a world where some characters have both male and female characteristics, how would the power dynamics and relationships in 'Attack on Titan' change? Another theme might be focused on how the Titan shifters' abilities interact with the futa physiology. It could add a new layer of complexity to the battles and strategies within the story.
One popular theme is the relationship between female characters in the Survey Corps. For example, the friendship and possible romantic tension between Mikasa and Sasha could be explored in a Yuri context.
Well, it can change the themes of the original story quite a bit. For instance, if male characters are genderbent into female, it can shift the focus on how society within the walls treats women. In the original 'Attack on Titan', women were in a rather complex position in the military and society. In a genderbend fanfic, this can be explored further. Maybe the female - genderbent versions of male characters face more discrimination or have to prove themselves in different ways.
I'm not sure specifically about really popular 'halo crossover attack on titan fanfic' stories. Fanfic popularity can vary a lot and depends on different fan communities. You might have to search on dedicated fanfic websites to find out which ones are getting a lot of attention.
One popular Naruto genderbend fanfic could be one where the female Naruto has different relationships with the other characters. For example, she might have a more sisterly bond with Sasuke, which changes the whole dynamic of their story arc. Another could be where she uses her femininity in a unique way during battles, perhaps using her charm to distract opponents while still having the same strong ninja skills as the male Naruto.
One popular coco genderbend fanfic might be the one where the main character's gender is swapped and they have to face different challenges in the story's world. For example, if the original male character is now female, she might experience discrimination in a male - dominated area of the story's setting.
There are often fanfics where the gender - bent characters have new relationships. Maybe Ben as a girl forms different alliances or has different romantic interests. It adds a new layer of complexity to the Ben 10 universe. Some fanfics focus on how the Plumbers' organization would be different with gender - bent characters in key positions.
One popular storyline is them facing a particularly difficult titan together. They use their unique skills, Levi's combat prowess and Erwin's strategic mind, to outwit the titan. It makes for an exciting read as they work in tandem.