It depends on the specific fanfic. Some fanfics might have Guts killing Griffith as a major plot point, while others could take a different direction and not have that happen at all.
Perhaps in this fanfic, Griffith has turned into something truly evil and a threat to the world Guts cares about. Guts, being the warrior he is, might feel it's his duty to put an end to Griffith to save others. Also, Guts could be driven by his own sense of justice. If Griffith has wronged innocent people, Guts may decide that killing him is the only way to set things right.
A unique take on their relationship. For example, if it shows a side of their bond that was not explored much in the original manga, like Casca's perspective on Guts' more reckless actions. It could also stand out with great character development, making them more complex and relatable.
One great example could be a fanfic that focuses on Guts and Casca's relationship before the Eclipse. It might explore their shared moments of trust and growing affection. Another could be a post - Eclipse fanfic where Guts is trying to help Casca regain her sanity. There are also fanfics that put them in alternate universes, like a modern - day setting where they have to face different kinds of challenges while still having their core relationship dynamics.
Yes, there are many Berserk fanfictions that focus on the complex non - romantic aspects of Guts and Griffith's relationship. For example, some may explore their friendship before the betrayal, their rivalry on the battlefield, or their mutual respect for each other's skills. These fanfictions can provide a deeper understanding of their characters and the overall story of Berserk.
In some fanfictions, their relationship can be seen as a source of inspiration. Griffith's grand vision might inspire Guts to strive for something greater than just survival. At the same time, Guts' unwavering determination can be an inspiration for Griffith to keep pushing forward in his own goals, all without any romantic or sexual elements.
Guts is purely fictional. It's a concept or character that exists within the realm of imagination and creative storytelling rather than being based on reality.