There might be. However, the availability can vary. Some fanfiction communities dedicated to 'Attack on Titan' may have such works. You could join relevant forums and ask for recommendations. It's important to note that not all of them may be of high quality, so you might need to do some sifting.
The unique take on their relationship. It offers a different perspective from the original story. It can explore new aspects of their bond, like how they support each other in this unexpected situation.
Some fanfics also focus on the psychological aspect of their relationship. Reiner and Bertholdt both have complex personalities and backstories. Fanfics might explore how they understand and support each other on a psychological level, perhaps dealing with their inner demons together.
One great fanfiction is 'The Trio's Bond'. It delves deep into the complex relationships between Reiner, Bertholdt, and Annie. It shows how their shared experiences in the military and their secrets bind them together in ways that are both heart - warming and full of tension. Another one to check out is 'Among the Three'. This fic focuses on their individual growth while also exploring their interactions with each other, giving a fresh perspective on their characters.
There's 'Together in the Shadows'. This fanfic focuses on the more private side of their relationship. It shows how they support each other during difficult times within the story's universe. It's a well - written piece that gives a lot of insight into their characters and how they feel about one another.
The theme of trust is crucial in 'Attack on Titan Reiner x Bertholdt fanfiction'. They have to trust each other completely in order to survive in the harsh world of Titans. Additionally, the theme of redemption sometimes shows up. If they make mistakes or have actions that they regret, they try to redeem themselves in the eyes of each other and also within the context of their friendship.
The popularity of 'Reiner x Bertholdt x Annie Fanfiction' lies in the complex relationships between these characters. They have a shared past and secrets that fans love to explore in fanfictions. Their different personalities also create a lot of interesting dynamics.
Fanfiction.net is also a great place to look. There are many 'Attack on Titan' fanfics there. Just type in 'Reiner x Bertholdt' in the search bar and browse through the results. However, the quality may vary, so you might need to read a few to find the really good ones.
There's a fanfiction named 'Reiner and Bertholdt: A Different Path'. In this story, it takes a different turn from the original plot and focuses more on their relationship outside of the main battles. It shows their more personal side, like how they interact when they are alone. And 'Hidden Feelings' is also a good one. It delves into the emotions that Reiner and Bertholdt might have for each other but keep hidden from others.
Reiner did die in the manga. His death was a result of a series of events and conflicts that had been building up throughout the storyline. It had a major impact on the plot and the other characters.