Lightbringer

Acquisition

 * Talk to Seeker of Whispers [Lightbringer Ranks] in Chantry of Secrets after attaining the first rank of the Lightbringer title.

Demonic Servants of Abaddon
This title effect, as well as the two linked skills Lightbringer's Gaze and Lightbringer Signet, work against the following foes:
 * Margonites
 * Stygians
 * Most Torment creatures (excluding Grasps of Insanity, Wrathful Storms, Scythe of Chaos Mesmers, Lesser Grasps and The Hunger)
 * The Blasphemy and Unbound Energies
 * All Shadow Army units in the Nightfall campaign (but not Shadow Army units in the Fissure of Woe)
 * All Nightfall exclusive Titans (Titan Abominations, Pain Titans, Madness Titans and all Titans in the Domain of Anguish), but not other Titans
 * Tortureweb Dryders and the Emissaries of Dhuum, but not Terrorweb Dryders or other Dryders
 * Varesh Ossa in both forms
 * Abaddon himself
 * All monsters in the Domain of Anguish