The Nazgul

The Nine were a group of nine men turned to wraiths by the rings of power.

They are all avaliable in the rise of the witch king expansion with the witch king, Khamul , Morgomir And the black riders hero horde.

On the other games various mods let you control the nine.

Lore
They were once great kings of men until  sauron the deciever   gave them each an ring of power. Over the years they turned to wraiths to server sauron.

After the witch kings demise there deaths followed shortly.

Heroes
Witch king

Khamul

Morgomir

Nazgul

Advantages
Nazgul are powerful heroes that can defeat battalions with ease

Disadvantages
With all their power the nazgul can be weak. They will die easily die when surrounded.They will fall easily to archers and heroes such as Legolas and Faramir when of their fell beasts .