Nazgûl Theme

[piosenniel]

No other blade, not though mightier hands had wielded it, would have dealt that foe a wound so bitter, cleaving the undead flesh, breaking the spell that knit his unseen sinews to his will

First, let me say that I do not believe that the Nazgul were dead creatures. I think they were men who by the power of the rings given them and the power of the One Ring through them had passed into a state between the actual mortal world and death. They were wraiths, spectral figures just on the edge of death.

Merry's blade did indeed strike a bitter blow in severing the fragile control that the Nazgul's soul had over its almost vanished, thinned out physical body. In doing so, the spirit/soul was unable to strike a mortal blow to Eowyn. But the spirit was still present, and fighting for control

. . . the great shoulders bowed before her

If Eowyn had not cleaved the head from the shoulders, effectively killing the physical body and releasing the soul, the Ringwraith may have bided his time and eventually come back in some other physical form.