Known as the greatest intellect of the Demon World, Dr. Oz has made countless brilliant achievements Creature Zero was also created to control the Demon Blade. Zero had envied the Demon Blade Grandark, who received much better treatment unlike a mere expendable being like himself. Although Zero had nothing in his possession, he had vast knowledge of the various research data from Dr. Oz's horrific experiments. With this knowledge in mind, Zero started to live as the doctor of the dark alleys.