Game of Thrones:

Melisandre- the red priestess of R'hllor, she who has visions in the flames and can kill with shadows. One of the more intriguing, mysterious figures in A Song of Ice and Fire. She initially believes that Stannis is the Prince that was Promised, the modern- day avatar of Azor Ahai, reborn in salt and smoke to face the Others and the great night. Readers of the books and watchers of the HBO show know that, despite her powers, she is fallible, makes mistakes- and it appears that she is badly misinterpreting her visions regarding the Prince that was Promised. But if not Stannis- who? 

This post will have spoilers for A Song of Ice and Fire. 

Melisandre is apparently a former slave who was raised in the red temple and at some point became a priestess. We know little of her other than that she is reputedly a shadowbinder from Asshai, and we've seen firsthand how she can kill with shadows, even giving birth to them and drawing from Stannis' lifeforce to give them purpose. For the first time in A Dance With Dragons we actually get a POV chapter from her perspective, and it's very interesting. A lot of the things we learn may not have relevance to the show, depending on how deeply they delve into her character, but for book readers there is a lot of info in that one chapter. And more questions than answers.    

She notes for example that many other priests and priestesses have been brought down by misinterpreting their visions, by seeing what they want to see- clearly not realizing that she is doing the same thing. And her visions clearly take a toll on her as well. 

The red priestess shuddered. Blood trickled down her thigh, black and smoking. The fire was inside her, an agony, an ecstasy, filling her, searing her, transforming her. 

Melisandre had practiced her art for years beyond count, and she had paid the price. There was no one, even in her order, who had her skill at seeing the secrets half- revealed and half- concealed within the sacred flames. 

So she is obviously very old. We also learn that she doesn't need food, and rarely sleeps- so is she even human anymore? We learn that she uses powders for various purposes, and for effect. But she is stronger at the Wall, which is intriguing. 

She was stronger at the Wall, stronger even than in Asshai. Her every word and gesture was more potent, and she could do things that she had never done before. Such shadows as I bring forth here will be terrible, and no creature of the dark will stand before them. With such sorceries at her command, she would soon have no more need of the feeble tricks of alchemists and pyromancers. 

"Call it what you will. Glamor, seeming, illusion. R'hllor is Lord of Light, Jon Snow, and it is given to his servants to weave with it, as others weave with thread." 

There are, as we know, others who can see in the flames. Moqorro comes to mind, the red priest who accompanies Tyrion briefly on his journey east and is later fished out of the sea by Victarion's sailors. His powers are formidable and some say his track record at predicting events is better than Mel's- he was sent by the high priest of R'hllor to meet with Daenerys, so he is obviously highly regarded by the priesthood? Are there others? Thoros of Myr has the ability to see visions in the flames, and has brought Beric Dondarrion and later Catelyn Stark back to some semblance of life, presumably using R'hllor's power. Can Melisandre do that? Judging from the show she can, as she returns Jon to life, and will probably do so in the book version as well.   

The crucial difference between Mel and the other seers is she is intimately involved in the war for the dawn, on the front lines- at the Wall. I expect her to bring Jon back to life, somehow, but what will that do to him? What can Jon and Melisandre accomplish together? Only time- and The Winds of Winter- will tell. But until then, going back to the Azor Ahai questions, it's interesting to see this passage from her chapter. 

I pray for a glimpse of Azor Ahai, and R'hllor shows me only Snow.