Ayorzén has agreed to help you gain access to Barad Cúron, but even with the Easterling's aid this mission will not be free of danger.
'Mithrandir has told me of his plan, and I will not speak against it. But I urge you to remain alert, ${PLAYER}, for many centuries have passed since the Tower of the Crescent Moon last fell into the grasp of evil. Even Mithrandir cannot say what you might find within. Gothmog alone would be threat enough, but while Sauron held our attention Gothmog had time enough to ransack Minas Morgul for its secrets; he may have prepared some defence or trap we cannot anticipate.
'I will give you one further warning. If the Khundolar Ayorzén does agree to help you with this, remain alert for any sign of treachery. I believe he will aid you for as long as his interests align with yours; see that they do and he may be worthy of trust. But if that becomes otherwise...
'Good fortune to you, ${PLAYER}. I think you will need it.'
Orcs and other foes remain a danger within Minas Morgul, and you should thin their numbers before setting Mithrandir's plan into motion.
Culang is standing watch near the entrance to Barad Cúron on the uppermost tier of Minas Morgul.