The hero of the legends, Rainer, was also a monster with powerful magical abilities. Other than that, some of the main characters in the anime didn't have as many friends as Reiner. For example, Alan in Attack of the Giants was a lonely man, but he had amazing strength and wisdom. If you want to watch an anime like Reiner's, where the character is a monster, you can look at Kirito in the Sword God Realm. He is a monster who has the ability to control virtual reality.
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.
It would likely make him more mature. Knowing about his parents would give him a different perspective on life. He might be less reckless in battles as he now has a family connection to think about.
One great fanfiction with this theme could be on Archive of Our Own. There are many talented writers who explore Link's past life in unique ways. Some might show him remembering his past life as a heroic knight in a long - lost era, with vivid descriptions of battles and his comrades from that time.
The emotional impact could be huge. Goku has mostly been without his parents in the main story. Remembering them in a fanfiction could bring out a sense of longing and sadness. He might feel a deep connection to his Saiyan heritage that he was previously unaware of. This could also lead to a newfound motivation in his battles, as he now has a connection to his roots.
I recommend "The Legend of Online Games". This novel is a gaming-game-otherworld-type novel. The protagonist comes to a mysterious challenge space. It's actually a world that looks like an online game. There are endless missions waiting for the protagonist to complete. And the benefit he received was to rule the entire world! The plot of this novel is very similar. Perhaps it's what you're looking for. I hope you like this fairy's recommendation. Muah ~😗
Yes, there are quite a few. You can start by looking on popular fanfic platforms like Archive of Our Own. There, you might find some well - written stories about Reiner and Mikasa. Some focus on their complex relationship considering their different allegiances in the original story, which makes for really interesting reading.
Once upon a time, in an old, abandoned mansion on the outskirts of a small town, there lived a dark presence. People said that late at night, you could see a figure in the attic window. A young girl, curious about the rumors, decided to explore the mansion one night. As she entered the dusty hallways, she heard strange whispers. The further she went, the colder it got. Suddenly, a cold hand grabbed her ankle. She screamed but no one could hear her. She was never seen again.