Unwanted Guests

Quest Overview
Summary:
 * 1) Clear The Labyrinth of the invading Dryder Force. you have 6..0 groups remaining.
 * 2) Return to Reaper of the Labyrinth for your reward. [sic]

Obtained from:
 * Reaper of the Labyrinth in The Underworld

Requirements:
 * Clear the Chamber

Reward:
 * 10,000 XP

Dialogue:
 * "The stench of the Terrorwebs still lingers in the Labyrinth. The Vengeful Aatxe have been enchanted by a Keeper of Souls. No blade, hammer, or spell in any world can do harm to them while the Keeper lives. Kill the Keeper to disable his potent magics, and the Vengeful aatxe will follow him into death. If you do this, the death god will look upon your actions and smile"

Followup:
 * None

Walkthrough

 * Before Accepting this quest make sure you clear the entire Labyrinth.
 * Make sure you do not have the Escort of Souls quest running concurrently.
 * After accepting this quest six different groups will spawn throughout the Labyrinth. Each group consists of one Keeper of Souls, three Terrorweb Dryders, and three Vengeful Aatxe.
 * Don't target the Vengeful Aatxe before the Keeper of Souls in their group is destroyed, since they are invulnerable to any attacks beforehand. Knockdowns and cripple still affect the Aatxes, which can be useful to limit the damage they can inflict.
 * Kill the Terrorweb Dryders if they are preventing you from safely reaching the Keeper of Souls.
 * The Vengeful Aatxes do not vanish on the death of the Keeper, they also do not lose their invulnerability. You will have to fully break aggro with them and be nearly off radar before they will vanish.  This may require having a party member sacrifice themself while the rest of the group moves out of range.
 * The best approach to this quest is to first free both the Reaper of the Forgotten Vale and the Reaper of the Ice Wastes. Then accept the quest and use the teleport function to attack the Keeper of Souls from behind. Be sure to study the patrol patterns of the monsters if you aren't familiar with them.