The Balrog vs The Witch King

[Gordis]

Originally Posted by Boromir88

Gordis, but that doesn't necessarily mean The Witch-King knew Gandalf's nature, and knew his full power. Because even though if Gandalf is sent back with enhanced powers, he still keeps them veiled.

I didn't try to imply that the WK was aware of Gandalf's death, resurrection and his "upgrade" to White Wizard. But the quote from RC says that the WK, already while hunting the Ring near Weathertop, did know that G. the Grey was a great power. Most likely they had occasions to meet before (in Angmar?)
And what being could make a nazgul pause? Calaquendi and Maiar - or something like Tom B. (Also pretty girls, in the Witch-King's case ). I think the nazgul were very good at recognizing incarnate Maiar - hadn't they watched Sauron for an Age?