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.
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.
If Lord Reiner is from a particular book or game, more context is needed. For example, if it's a character from a fantasy novel, we would need to know the plot of the novel, the world it is set in, and his relationships with other characters to tell his full story.
There could be stories about how he dealt with new musicians or young talent. His high standards might have been overwhelming for those just starting out. He expected them to quickly adapt to his way of working, and if they didn't, it could lead to some rather unpleasant experiences for the budding musicians.
Love and sacrifice are common themes. Often, Reiner has to sacrifice something for the sake of love in these fanfictions. It could be his position in the Legends world or his own safety.