Natalya

Natalya is a former Assassin-turned Demon Hunter.

Kurast
Natalya was in Kurast during the time of the awakening of the Prime Evils. She arrived and waited for further orders. During that time, she rejected an offer from Asheara to join the Iron Wolves, and talked to Hratli about weapons. She made many around her uneasy.

A week after her arrival, she encountered a group of heroes who were in pursuit of the Dark Wanderer. She provided them with information, but could not help further, as she was obliged to stay at the docks to await further orders. By the time the group defeated Mephisto, she had left the area to head north into the lands.

Dealing with Demons
A few years before the End of Days, Natalya left the Viz-Jaq'taar, instead taking up the cause of the Demon Hunters, seeking redemption. She focused on the hunting of demons, gaining some small semblance of peace from doing so.

Diablo II
Natalya appears as an NPC in of Diablo II, found in the Kurast Docks. Despite a shared class, she has no unique dialogue for an Assassin character.

She disappears from the area after Mephisto is slain. According to her dialogue for when is completed (which the player never hears due to her disappearing), she received new orders to head to the northern lands of the Barbarians, but wouldn't say why.

The item set, Natalya's Odium, is named after her.

Diablo III
Natalya's Vengeance is an item set in Diablo III, used by Demon Hunters. The items' description provide vague hints at her activities post-Diablo II.

Trivia

 * As Natalya plays only a minor role and serves no particular in-game function as an NPC, she is mostly believed to be nothing but a preview regarding one of the new classes in the Diablo II: Lord of Destruction expansion.
 * Cain identifies her as a member of an Order called "Khral-Harzhek", while the Assassins are later known as the Viz-Jaq'taar, and the Book of Tyrael explicitly states she was once a Viz-Jaq'taar Assassin.
 * Natalya is a Slavic form of the name Natalie, making Natalya one of the few characters with Slavic names who are not confirmed to come from Ivgorod.