Charles Manson is just one person. Different people equals different personalities. Charles Manson may have done disturbing acts in his history. However, it doesn't finalize that he is the most disturbing serial killer in existence. Throughout history serial killers have had done far worse acts than Manson can ever do in his entire life. Adolph Hitler and the Nazi Party for an example during the second great war.
As for today, their are too many people in this world to determine who is more sickening than Manson. Everyone has skeletons in their closet. It's just a matter of time to see somebody to have more skulls than Manson.
There are many examples of known serial killers that are responsible for much larger numbers of homicides than Charles Manson. Charles Manson was responsible for the murders of 7 people, but he did not commit the murders himself, he ordered his followers to commit murders. Since Manson there have been several notable and disturbing serial killers such as John Wayne Gacy, who killed over 30 young men, Ted Bundy, who murdered dozens of young women, and Pedro Alonso Lopez, also known as the Monster of the Andes. Pedro Alonso Lopez is by far the most disturbing serial killer, he confessed to killing more than 300 young girls from the ages of 9-12 in the countries of Ecaudor, Peru, And Columbia. Unlike Gacy and Bundy who were ultimately captured and put to death, Lopez served only 14 years in prison in Peru for the murders of over 50 girls whose remains were uncovered. He was then released and served a few more years in Psychiatric prison in Columbia, but was also released from there and he has not been seen since the late 90's. The fact that Lopez may still be alive to this day and responsible for fresh murders in that South American region is highly disturbing.
Charles Manson is a very troubled and insane person who did a lot of violence. But then again every serial killer has wreaked his own kind of havoc. I do not think it is possible to value them in terms of their disturbed nature because all of them are insanely violent.
No, there are not more disturbing serial killers than Charles Manson, because he killed only for the fun of it. Manson had no other purpose other than that he enjoyed what he did. He is the most ruthless form of terrorist. Manson was a predator who victimized people in every way that he could. He was the worst.
Charles Manson is a despicable human being and a notorious killer. It is not likely that anyone could be more disturbing than he is. There is not really a lot of profit in discussing which killers are more disturbing than others. Manson is probably an example of the worst kind.