Jackie, the lightning is a Zenofex (Alien Skin) effect. The sky is from my collection of real skies, just waiting to be used like this. :) Whenever I see a cool looking sky, I take some shots and store them in a folder. Comes in handy!
Very cool image. Would it be possible to do it so the lightening bolt was behind the vulture? I think that would notch it up a bit, make it even more striking, for me at least.