The Witch-King

The Witch-King is one of the Heroes available for Mordor. He can be recruited from the Citadel.

He is the leader of the Nazgûls and the strongest one.

Abilities
The Witch-King screeches, getting nearby enemy units to flee. The Witch-King provides 50% Damage and Armor in a wide area.
 * Screech
 * Leadership

Advantages
The Witch-King is the strongest Nazgûl and also their leader. For that reason, it is harder for the enemy to bring him down. You can send him in first instead of other Nazgûls in order for him to soak in more damage and for the rest of the Nazgûls to deal damage. His Leadership will provide your troops with a considerable amount of damage and armor. Have him near your army for a period of time for your troops to deal the most damage possible.

Disadvantages
Just like with the Nazgûls, the Witch-King is vulnerable to ranged attacks. That means that archers and defensive buildings, such as Keeps will deal a lot of damage to him. Prioritize them first. In addition, Gandalf's Istari Light will also deal a lot of damage. Try to avoid getting in battle with him.