Scribbles on the Wall of Valencia Castle

It happened during a field study to Valencia Castle. As I reached the peak of the castle by climbing a ladder, I spotted a scribbling... Yes, it was a scribbling. It didn't seem like a code, and it was just written by someone... It was "Igor Bartali was here. - Igor Bartali the Great Adventurer," followed by a meaningful line: "Igor Bartali - The illusion of Black Spirit makes me stronger, but could it also be dangerous?"