Question: is ner'zhul the lich king?
Answer: Agreeing to enter into the service of the demon once more, Ner'zhul was bound to the Frozen Throne. His perception, mental powers, and magical abilities expanded tremendously. Thus the Lich King was born. As the Lich King, Ner'zhul would rule the Scourge alone until merging with Arthas Menethil.