Nazgul definitely shines in Expanded. There are multiple strategies to develop with them and you can heavily,
heavily abuse your opponent's fellowship whatever type.
They have always been the leader in crowd control.
Nertea gave them easy mono-culture hate and help with tank companions.
Easiest site manipulation.
Easily take advantage of burdens and threats.
Possession hate.
The only thing they aren't incredible at is taking down conditions. However, they are easily supplemented with
Grima, Servant of Another Master and
Saruman's Power.
Just plain mean.