The second martial soul skill book of the Heavenly Dragon Eight was a very important tool that allowed a fighter to have two different battle skills. The spirit was a special ability in novels that allowed a fighter to have different weapons and attack methods, while the second spirit skill book allowed a fighter to have two different spirit skills. After using the two spirit skill book, the fighter can transform one spirit skill into another spirit skill. This kind of transformation can be one-way, that is, can only transfer one spirit ability to another spirit ability, it can also be two-way, that is, can simultaneously transfer two spirit abilities to another spirit ability. The usage of the second martial soul skill book required a certain amount of qi and blood value or martial soul energy. Fighters could use two spirit skill books in battle to increase their fighting ability, especially when facing powerful enemies, using two spirit skill books could give the fighter a greater chance of winning. The second spirit skill book of the Heavenly Dragon Eight was a very important tool that could allow a fighter to have two different battle skills to increase their battle ability.