Steam

Water driven to vapor by living force: obscuring, scalding, and everywhere at once. Steam is the most temperate of the bright quasi-elemental planes and the least trustworthy.

d’Ouhb holds it. She is the Mistress of Mists, the Scalding Seductress, and her portfolio is deception, allure and manipulation. Her mark was cut into the Mól sigil-hall beneath the slaver camp alongside Luhthar’s (S1E10), Water and its bright mixture set side by side in the stone.