In certain fanfiction works, Tatsumi is indeed made into Esdeath's pet. This can be a way for writers to explore darker or more extreme versions of their relationship. It might involve Esdeath treating Tatsumi in a demeaning way at times, or it could also lead to a strange form of affection developing between them as the story progresses. It really varies from one fanfic to another.
If Naruto is Esdeath's brother in fanfiction, they could embark on adventures across different dimensions. Since Naruto has experience with his own world and Esdeath with hers, they could explore new lands together. They might encounter strange creatures and powerful enemies. Along the way, they could learn from each other's fighting styles and abilities, Naruto teaching Esdeath about chakra and she teaching him about her own brand of combat techniques. And they could also be on a quest to reunite their fragmented family or uncover a long - hidden family secret that has the power to change their worlds.
Yes, it can be quite popular. Naruto is from the Naruto series and Esdeath is from Akame ga Kill. Combining them in a love fanfiction creates an interesting crossover. Fans enjoy exploring the dynamic between two very different characters from distinct universes. It allows for creative interpretations of how their personalities would interact in a romantic context.
Some characters might adapt well due to their own desires for power. For example, Sasuke could see the peerage system as a means to gain more strength to achieve his revenge. He would likely be drawn to Esdeath's strength and might be willing to submit to her in order to learn from her combat skills.
Tatsumi is very likely to be involved as he has a significant relationship with Esdeath in the original story. Her subordinates in the Jaegers might also be part of the fanfic. They could be shown as being protective or having mixed feelings about her pregnancy.
Well, in this fanfiction, Naruto could join Esdeath in her military campaigns. Since Naruto has his own set of powerful jutsu, he could be a great asset. The plot could revolve around how Naruto adapts to the new world's rules and politics. He might be shocked by the harshness of Esdeath's world but still tries to bring some of his positive values. They could form an unlikely alliance, and Naruto's presence could start to change the power dynamics in Esdeath's territory.
In this fanfiction, Tatsumi could be sent on a special mission that requires him to infiltrate Esdeath's inner circle. He disguises himself and gets close to her. Esdeath, who has a sixth sense for these things, suspects Tatsumi but plays along. As they interact more, there is an underlying tension between their opposing ideals, yet also an attraction that neither can fully understand or deny.
One possible plot could be that Tatsumi and Esdeath, after getting married, try to find a balance between their different ideals. Tatsumi, with his sense of justice, might influence Esdeath to be more empathetic towards the common people. They could face challenges from the political unrest in their world, and together they use their combined strength and influence to bring about positive change in their society. Also, their relationship could be a source of conflict among different factions who either oppose or try to use their union for their own gains.
I'm not sure specifically about 'lemon' fanfiction as it often involves inappropriate or adult - themed content. However, there are many regular Tatsumi and Esdeath fanfictions on various fanfiction platforms. You can try Archive of Our Own or Fanfiction.net and search for their relationship - based stories that are more in line with general storytelling and character exploration.