Complete Monster/Yami no Matsuei


 * Handsome, charming Dr. Kazutaka Muraki from Yami no Matsuei. As of the start of the series, he's already spent several years systematically kidnapping, dismembering, and vivisecting small children (like, raping adolescents and infecting them with slow, agonizing fatal diseases (like  ), and seemingly murdering pretty much every grown woman he comes across, whether to use them in scientific experiments to attract the attention of the Shinigami or just for lulz. All of this murder, torture, and rape is really only the means he uses to the end of fashioning a good old Mind Rape, whether it's mentally torturing a girl madly in love with him into developing split personalities (like  ), mind-controlling suicidally depressed pop stars into becoming blood-drinking monsters (like  ), or stalking and harassing one of the Shinigami  with so much misdirected guilt that he finally manages to drive him into a catatonic state, in which state he fully intended to vivisect the guy and use his powers