Natalya is an NPC found in the Kurast Docks. She is located on the large stone island south of the stash and waypoint, where she remains until nearly the end of the Act, when she vanishes without a trace. Not much was thought of Natalya during the early days of Diablo II, but once the expansion was announced and the Assassin character was revealed, players realized that Natalya was an Assassin, meant as a sort of Easter Egg/sneak preview of the class that Blizzard North knew they would be adding in the expansion pack.
She does not give any quests or quest rewards, but her dialogues are interesting for the plot points they touch on, and what they reveal about the nature of the Assassin class.
Act Three Dialogues
Introduction
Greetings, hero. I've heard of your exploits and . . . I'm quite impressed. Very few mortals are capable of dealing with the Three and their minions as you have.
My name is Natalya. I am a hunter of Evil, part of an ancient Order sworn to hunt down corrupted sorcerers.
If I could, I would gladly join your quest to stop the Three. But I must wait here for further news. I can't predict what will happen, but the danger is greater than we can know.
Until I receive my orders, I'll assist you with the information I have.
The Golden Bird
Quest Tips
I'm having fun just watching you run from place to place searching for a Golden Bird. Some hero you are.
My Order has been keeping watch over Ormus for many years, now. He seems to champion the cause of good, but who knows what shadow lurks within his soul?
The Blade of the Old Religion
Quest Tips
Don't let the Gidbinn's size fool you. Though it is only a small dagger, it holds tremendous power when in the hands of a true Skatsimi mage. The Gidbinn is one of the few remaining relics of Skatsim, the Old Religion. It is reputed to have great powers.
You'd best get back out there and find that blade. The jungle creeps further into this camp by the hour.
After Completion
You are truly amazing, stranger. There are precious few items in the world that would tempt me to go up against the Children of Zakarum and their midget minions.
Khalim's Will
Quest Tips
I must admit, your foolish quest made little sense to me. But now I see the value of your actions. I believe you do possess great wisdom.
After Completion
Beware, my friend. Sankekur may be the most powerful mortal in the world. He controls thousands of fanatical worshippers and embodies the Lord of Hatred himself. His death will be no easy task.
Lam Esen's Tome
Quest Tips
I've heard of the Black Book. My Order's code is based on many of its passages. If you find it, I will be greatly impressed.
After Completion
So, you've returned with the Book. You surprise me. You must be very resourceful.
The Blackened Temple
Quest Tips
Beware the followers of Zakarum. Their fanaticism is their greatest weapon.
I respect your need to do this. Honor demands that you see this through. Yet your chances are so slim...
After Completion
I can hardly believe you did it. Your power blankets you like a shining aura.
The Guardian
Quest Tips
Now you rush to face Mephisto. Don't give in to your hatred. That is his greatest weapon against you.
After Completion
Natalya vanishes from the city after Mephisto is defeated, apparently having finally received her orders, or else taking word of the battle against the Brothers back to her superiors in the Assassin order.