The Aetherial Witch

This is an Act 4 side quest offered by Captain Reave after completing the Betrayal at Fort Ikon quest.

The Legion is harboring a Possessed witch named Anasteria, and Inquisitor Creed has ordered her not to be harmed. Captain Reave however blames her witchcraft for the betrayal by Commander Lucius, and asks you to deal with her.

Objectives
Optional:
 * Speak to Anasteria at the Fort Ikon Prison
 * Slay Anasteria
 * Report to Captain Reave at Fort Ikon

Guide
Anasteria is located in the Fort Ikon Prison. Talk to her and decide whether to kill her or let her live.

Benefits to letting her live

 * Unlock the Outcast faction, equipment, bounty table, and quest line, which increases Outcast reputation and decreases Black Legion reputation.
 * Access to some of the best Aether Resistance augments in the game, able to be applied on weapons and armor.

Benefits to killing her

 * Unlock the Fort Ikon Prison dungeon with Anasteria as a boss at the end and a great source of The Black Legion reputation farming, Elite mobs, and gear.
 * Access to Outcast's Secret, a Legendary helm that only drops from Anasteria.

Rewards
Spare Anasteria:
 * Anasteria will then offer the Power of our Enemies quest.

Kill Anasteria:
 * Captain Reave will then offer the Cult Activity side quest.