Sja-anat

One of the Unmade, called the Taker of Secrets, who alters any spren she touches. She appears as a black shadow with white eyes. Her spy swims the Purelake, and in Kholinar she warns Shallan from a mirror that the Oathgate is a trap, then makes the crossing to Shadesmar safer. She insists she is no longer Odium's servant and is not an enemy.

1. Her shadow-faced spy is described swimming through the Purelake with a knightly escort. source

1. Shallan glimpses something in a palace mirror in Kholinar turn and look at her with sudden surprise. source
2. Sja-anat tells Shallan she is not an enemy and that the heart is a trap. source
3. From a mirror in the Oathgate control building, she names herself and warns Shallan that the gate is trapped and will not work as hoped. source
4. Her touch on the corrupted spren in the gate makes the crossing of Shallan, Adolin, Kaladin and Azure to Shadesmar safer. source

Allied with

Shallan Davar