Complex sentence: Using their dark magic, he had himself transformed into the unstoppable undead Judge Death and along with the "Sisters of Death" and his fellow Dark Judges (as well as the influenced Deadworld Judges), he wiped his world clean of all life.
Split into simpler sentences: Using their dark magic, he had himself transformed into the unstoppable undead Judge Death. Along with the "Sisters of Death" and his fellow Dark Judges (as well as the influenced Deadworld Judges), he wiped his world clean of all life.