Fucking 10/10 stuff. Kel'thuzad's arrogance, him contemplating rebellion against the Lich King, followed by him whimpering in stark terror, realizing he had no choice other than serve his master, once again followed by him kneeling in submission to his dark master.
Also, Ner'zhul throwing some neat quotes that are worthy of making a signature out of them.
"Let this be your first lesson. I have no love for you or your people. On the contrary, I intend to scour humanity from this planet, and make no mistake: I have the power to do it."
"Immortality can be a great boon. It can also be agony the likes of which you have not yet begun to fathom. Defy me, and I will teach you what I have learned of pain. You will beg for death."
It oozes quality. The quality that we need back in the lore. This is how you develop characters.