Unwanted Guests

Overview
Summary:

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"

Walkthrough
Upon accepting this quest, quite a large number of monsters will spawn all around the labyrinth area. There will be a few Keeper of Souls, some more Terrorwebs and a lot of Vengeful Aatxe. So once again it is best to have the whole area cleared before taking on this quest. The Aatxe indeed are invulnerable. You have to manoeuvre past them to get to the Keepers. Kill the Keepers and the Aatxes will die, too.