How voodoo practitioners use voodoo dolls to cast a very powerful spell on someone

Voodoo dolls are used to represent a specific person and transferring an intent from one person to another resulting in a very powerful spell taking effect.

The sticking pins in the doll is not to cause pain in the person the voodoo doll is associated with, but rather to pin a picture of a person or a name to the doll.

A voodoo doll can be used to bless or cause harm, this means a voodoo doll by nature is neither bad or good. The intent of the spell determines morality.