Secret Files and Origins Superman, inhabiting the Thought Robot, delays Mandrakk, enough to have him battled by his son, Nix Uotan, and killed during the Final Crisis by the Green Lanterns.
Secret Files and Origins Superman, inhabiting the Thought Robot, defeats Mandrakk/Dax Novu. Later, a different incarnation of Mandrakk (Rox Ogama), battles his son, Nix Uotan, and is killed during the Final Crisis by the Green Lanterns.