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.
There's also 'Dimitri and Anastasia's Adventure'. This one takes the characters on an exciting journey. It combines elements of mystery and romance as they face challenges along the way. The character development in this fanfic is top - notch, which makes it stand out.
Well, if Dimitri is a fictional character in a novel, his back story might include things like his upbringing in a small town, his relationships with family and friends that shaped him. Maybe he had a difficult childhood with some sort of trauma that led him on a particular life path. Without more context, it's hard to give a detailed Dimitri back story.
I'm sorry, but I have no information indicating who the author of the 'alpha dimitri novel' might be. It could be an indie author or something not widely publicized yet.