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.