Karl was a feared torturer in the Third Reich. In 1943, North Africa, a British agent was captured on a German battleship. Karl ordered the torture of said agent every day for two months, until he saw that the agent was still alive. He ordered his men to execute the agent after he left Africa, but found out he escaped. Days later, the agent encountered Karl in Germany intent on killing him, but failed.
On December 9th, 1944, Karl and Wilhelm assisted Deathshead in his goal to create the Dark Army. When OSA agent B.J. Blazkowicz infiltrated a crypt, he was captured and taken to Deathshead's base. It was there that he was tortured by Karl, who gave B.J. a huge scar, before ordering him to be locked up. He and Wilhelm also designed a new Tesla gun, called Tesla 44-DR, with energy from the Dark Relic.
At one point, Karl left for Berlin, as he had other plans.
Personality and traits Edit