What is the most vicious curse you know or think of?

Shaman's Blood Curse-Many years ago, among the shaman wizards in Northeast China, there were very few with extremely high morality and broad vision. It is said that these shamans know a very powerful spell, that is, the blood curse. Once cursed, no one can solve it, and they are all dead! There is only one way to crack it: help the caster kill other cursed people, so that he can escape ... "Shaman blood curse" is called the most poisonous because other curses are caused by the death or misfortune of the cursed person, but this is to make this person become a homicidal maniac to kill others ... Although he can escape death in the end, he can't escape his inner nightmare.