Oh wow, this is beautiful and so very Sauron I love how you've split it with the "good" or at least seductive side and the Dark Lord evil side. I especially love the contrast of his eyes, with the right eye reminding me of the Eye, while that beautiful, golden left eye is gorgeous, but has an unnerving quality to it as well. And I love what you did with the red highlight by his left eye, too.
I like also how you carried the design for his headdress over through both sides and how it complements the shape of the Ring letters in the background. And that animation with the sparks is the perfect final touch. This picture stunning shows Sauron's power, dark beauty, and grace, while also making it clear that he is dangerous and very dark. Love it!