The Charmed Ones in a Parallel World are an evil trio of sister witches. They rule their universe with fear and an iron boot. They are quite powerful and formidable. They rule from their home, The Halliwell manor.
They are not corrupted or fallen versions of the heroic Halliwells ; their universe is one where motives and desires like theirs prevail. It is the counterbalance of the universe the series' main characters inhabit, and so there they are still the guardians of what should be for their world. One of their fiercest enemies is the 'Demon' of Hope, Barbas, who is equally as annoying and persistent in his way as main-Barbas is for the main-Halliwells, since Hope and Fear never really go away. Despite natural antagonism, they show that they really are the equals of the main-Halliwells when they agree to mistrustingly cooperate to undo the damage caused by the alliance of their like minded Elder Gideon in both worlds. While not seen, it is said that their world suffered from this alliance and its consequences as well. While the Main-Halliwells' world became rigidly good (with horrific consequences for even the smallest and simplest of wrongs, all accepted by a psychotic populace), the world of the evil Halliwells became one where even a small good deed like helping someone with driving directions was similarly punishable. Despite worries from both sides that the other simply could not be trusted, both wanted safety and stability for those they cared about enough to do what they had to and part ways. After the two Leos resolve the crisis involving Gideon(s) and save their unborn sons in the process, both universes are restored to normalcy and separateness. The Evil Halliwells are not seen again, which, given that each side tried the exact same tactics against each other to no effect, is just as well.