It is not uncommon for a sociopath to have a side-kick. Sociopaths have no genuine empathy, although they can typically fake it rather well. They tend to find people who are easy to manipulate emotionally, and draw them deep into their personal orbit, although it is mainly for their own selfish purposes. They use and abuse them emotionally (google “cycle of abuse”) so even though they are treated badly, they are always brought back in, and the dependency relationship in intensified.
Charismatic sociopaths can have a lot of dependents. EG: Charles Mansion and cult leaders.