Agatha is a val'kyr in service to the Dark Lady. This is the first person new Forsaken players meet, as she is the one that raises them back into the world of the "living".
She is present for the meeting between Garrosh and Sylvanas, where Sylvanas reveals that the val'kyr have joined the Forsaken. Agatha then resurrects the nearby fallen corpses as Forsaken, much to the disgust of Garrosh and High Warlord Cromush.
Agatha later helps the player by taking them to Fenris Isle and aids the player in fleeing when the refugees from Hillsbrad become Worgen. Agatha later aids in the resurrection of Lord Godfrey and his lieutenants.
When Lord Godfrey betrays and kills Sylvanas, Agatha and her fellow val'kyr — Arthura and Daschla — sacrifice themselves to resurrect the Dark Lady.
Agatha yells: Rise, Hillsbrad Refugee! Become Forsaken!
Agatha says: Death is only the beginning.
Agatha says: Different master, same insatiable thirst for power.
Agatha says: Do you feel it, <name>? The darkness surrounds us.
Agatha says: I long for the frozen wastes of Northrend.
Agatha says: I sense doom in your future, <name>.
Agatha says: Life is meaningless. It is in the afterlife that we are truly tested.
Agatha says: Rise, Forsaken!
Agatha says: RUN!
Agatha says: Run...
Agatha says: The warmth of this place sickens me.
Agatha says: This way, <name>. We will take them by surprise.
Agatha says: Through me the Banshee Queen sees all...
Agatha says: Waste no time, <name>. We mustn't keep the Banshee Queen waiting.
Agatha says: We are bound to her, sisters...
The names of the three val'kyr are a reference to the three Precogs in the movie "Minority Report". The Precogs in the movie are named Agatha, Arthur, and Dashiell. In the movie, Agatha is the strongest of the three and most featured, similar to her Val'kyr counterpart. After encountering the Human Leaders inside Fenris Keep she also directly quotes Agatha's lines from the movie ("Run... RUN!!!!") which are also spoken during a very intense scene.