Kinvara is a Red Priestess, one of the high-ranking leaders in the faith of R'hllor, the Lord of Light. Her full title is "High Priestess of the Red Temple of Volantis, the Flame of Truth, the Light of Wisdom, and First Servant of the Lord of Light".
Kinvara meets with Tyrion Lannister and Varys in the Great Pyramid of Meereen, as Tyrion plans to ask her assistance in convincing the people to follow Daenerys as their guardian and protector rather than a conqueror or an invader. Tyrion greets her in Valyrian but she stays silent until she states, in the Common Tongue, that he does not need to persuade her into helping. Kinvara is sure that Daenerys is the one who was promised, using her freeing of the slaves and her dragons as examples of her claim; Kinvara is thus happy to assist Daenerys's associates however she can. Before she and Tyrion can complete their agreement, Varys interrupts, pointing out that Melisandre had proclaimed Stannis Baratheon to be the one who was promised, and that he was defeated by Tyrion in the Battle of Blackwater and later at Winterfell, the second time for good. He complains about how religion is overly self-assured of its own tenets; how everything is the "will of the Lord", and asks Kinvara why he should believe in her words when another Red Priestess was wrong. Kinvara states that everything is the will of the Lord, but that men and women can commit errors. She asks him if he remembers what the voice in the flames said when the "second rate sorcerer" threw his man parts into the fire, or if he knows who was speaking on the other side, rendering Varys speechless. She asks if he needs her to speak the very same words, or to identify the speaker; Varys cannot bring himself to answer. As Kinvara turns to leave, she assures Tyrion that she will call on her best priests and preachers to speak about the Queen through all of Essos.
A high priestess of The Red Temple of Volantis who serves the Lord of Light, Kinvara firmly believes that Dany is the fulfillment of an ancient prophecy. Tyrion Lannister recruited Kinvara to wage a propaganda campaign for Dany using her priests and priestesses.