Matthias tried to reason with Arthas, but Arthas killed him by running him through with Frostmourne. Ner'zhul was delighted by this, declaring that he and Arthas were now free to merge into a single glorious being. Arthas rejected this offer, stating that once he had the power of the Lich King, no one would tell him what to do again. He impaled the stunned Ner'zhul with Frostmourne, becoming the dominant personality of the Lich King and ending the dream.