Is the unnamed soul an ideal master? The Ideal masters are the gods of the Soul cairn. Necromancers make deals with the ideal masters. In exchange for souls the Necromancers get the ability to summon powerful beings from the soul cairn. The true form of the ideal masters is unknown. While in the Soul Cairn the Dragonborn makes a deal with an unnamed soul. The soul wants the skull of his horse Arvak in return the Dragonborn gets the ability to summon Arvak from the soul cairn. Was this soul maybe one of the ideal masters and did the Dragonborn make a deal with an ideal master?