Excellent lighting, this is definitely the archangel that kept the werewolves,vampires, and demons at bay in innistrad, as somebody who primarily runs with a black deck based around the inistrad collection this picture makes me shudder.
It's bugging me that Avacyn's wings and spear blade look... unfinished. The darkened area around her eyes also seems too large. Though, I realize, given the source of the light, her eyes would likely appear as they are now.
I do love the dynamic pose and overall composition. I could just imagine her descending from the sky to rescue a band of cathars or villagers; prepared to strike down their fiendish harassers.