Two witches - Phobia and Nausia befriended young Judge Sidney De'ath and turned him into undead monster Judge Death. Three of his fellow Judges soon followed him into undeath and together they murdered everyone on their world, after declaring all life a crime. This was the birth of the Dark Judges.
In the Judge Anderson story 'Lucid' (Meg 238-241), Anderson is attempting to destroy the bridge connecting Deadworld to Mega-City One. In a final desperate fight, the two sisters summon three other 'family members' - Pustula, Ephemera and Dementia. But it's not enough. The bridge crumbles and the undead clan are banished back to their own world/dimension. But as they vanish, they promise to return, and when they do, they will kill Anderson.