The Breaker of Oaths can teach you to become a Warlock of the Mists, a class specialising in the darker arts of the Azmeri. One powerful ability you can choose is Blood Hunt, which lets you consume corpses to gain more damage and protection against monsters that share a creature type with the corpse. The Breaker of Oaths can sell you additional corpses of exotic types, and these can also be used as powerful spectres. The Warlock of the Mists also gets access to many other abilities including a trio of new curse skills.
Wild Wisps can be used to purchase special corpses from the Breaker of Oaths
The Breaker of Oaths can teach you to become a Warlock of the Mists, a class specialising in the darker arts of the Azmeri. One powerful ability you can choose is Blood Hunt, which lets you consume corpses to gain more damage and protection against monsters that share a creature type with the corpse. The Breaker of Oaths can sell you additional corpses of exotic types, and these can also be used as powerful spectres. The Warlock of the Mists also gets access to many other abilities including a trio of new curse skills.
Yes:
(During the Path of Exile: Affliction Content Reveal it was mentioned that Vivid Wisps were associated with the Primal Huntress and Primal Wisps with the Warden of Eaves, however this has since changed to the above)