Karlof is the current Elemental Master of Metal, former aeronautical engineer in Metalonia, and a contestant in the Tournament of Elements. A brutish and often arrogant man, Karlof thought the Tournament would be entertaining, but he quickly started a rivalry with Kai, who ultimately defeated him during the first round. He was then forced to work in Chen's noodle factory, where he befriended Cole. Together, they built a Roto Jet and successfully escaped from the factory. Karlof and the other Elemental Masters sabotaged Chen's plans to hold all the elements for himself but failed to prevent his followers from becoming fake Anacondrai. The Elemental Masters united and faced the Anacondrai warriors at the Corridor of Elders. Despite their best efforts, they were overpowered by their adversaries until Garmadon sacrificed himself to curse Chen's army. Months later, Nadakhan imprisoned Karlof and the other Elemental Masters in the Djinn Blade. After Jay made his final wish, recent events were erased and he was freed. Not long after, Karlof was captured by the Vermillion and forced to help construct a machine for their masters. Eventually, he was freed from captivity by the ninja. After the supposed demise of the original ninja, Lloyd recruited Karlof and many others into a new team in a bid to resist Lord Garmadon's oppressive rule.