Marduk Blackpool was a Death Knight of the Scourge. Although he had rendered distinguished service to the Scourge, the Lich King seemed to have little regard for him. After the Battle of Caer Darrow, his runic sword, which possessed powerful dark powers, had been broken, greatly reducing his fighting strength. The Lich King had then sent him to Scholomance to "retire."
This left Marduk seething with resentment. I bled and risked my life for the Cult of the Damned and the Scourge. Why won't they let me return to the Scourge capital in Northrend? What am I doing here teaching novices?
The half of Marduk's broken sword lost in the Eastern Plaguelands still contained terrifying dark powers. That broken blade had even corroded a huge gash into the earth, which was known as Plague Mark.
Although Marduk was reasonably strong, they had clearly chosen the wrong person to threaten. Even Arthas, as the Lich King, could not keep Patrick from leaving when they faced each other. In terms of arcane mastery alone, Patrick, one of the Kingdom of the Elves' foremost Arcanists, was certainly no less accomplished than Ner'zhul.
Moreover, during the battle at An'telas, Arthas had lost many of his forces to Patrick. Although Arthas had ultimately isolated Patrick's devastating weapon-Arcane Mass Point-with powerful magic, Patrick, at the Legendary rank, already had the strength to fight a Demigod two ranks above him.
Such fighting strength was clearly beyond anything Marduk Blackpool and Vectus could compare with. Bound by Patrick's spiritual power, the two were dismembered as space was torn apart, leaving only severed limbs.
You ask why he did not simply cremate them? Using fire in an enclosed underground space like this would instantly fill the place with scorching heat and consume all the oxygen. As a result, every