The Mystic Knight

The novella is about a guy named Max who finds a mystic knight helmet while exploring a cave. The helmet then chooses him as the successor of the previous knight who own the helmet.  His job is to find a magical weapon called the Doom Blade and destroy it but unfortunately someone finds the blade first and gets possess by it.  Max must find a way to defeat the person possessing the Doom Blade and destroy the doom blade before there is deadly consequences