It's not a given that he won't be able to dispel it. And what if he uses Spirit Link?
2 Nazg
Well, there's nothing you can do about summoning anymore ;) I was talking about fighting darkness, berserkers and mind control are a terrible evil.
Bow down and hear our cry,
Our earthly rulers falter,
Our people drift and die,
The walls of gold entomb us,
The swords of scorn divide,
Take not thy thunder from us,
Take away our pride.
G.K. Chesterton: English Hymnal