Adria (Diablo) Edit
Adria the Witch' is an NPC and quest-giving character deeply involved in the story of Diablo 3. While apparently friendly and helpful in her role as Leah's long-lost mother, Adria harbors a secret agenda that leads up to the biggest plot twist of the story. Spoiler details below.
Adria was first introduced in Diablo 1, where she was an NPC merchant who sold potions, spellbooks, and various sorcerer items. She was not seen in Diablo II, but returns in Diablo III. She is not a merchant this time, but a story-teller and quest-giver who assists in the battles against the Prime Evils in Acts 2 and 3, before springing her big surprise leading up to Act 4.