Heinrich von Raitenau, and the great grandson of Adam. He and his sister, Christine, were used by Heinrich as Sinners for the new strains of GUILT in Under the Knife 2. During the raid on the new Delphi hideout, Karl and Christine were discovered in the depths of the hideout. After Adel Tulba utilised a serum designed to cure GUILT, the GUILT in their bodies go out of control, and Derek Stiles had to operate to save them.
Karl is a Sinner for the mutated Kyriaki encountered in Under the Knife 2.