An ethereal and mystical windstorm swirling with hues of blue, silver, and violet, representing arcane power. Glowing, runic symbols of Mystra faintly visible within the gusts, radiating divine light. The storm forms a cone-like shape, with feathers of shimmering white scattered within the currents. The background is a dark void with a faint celestial glow, evoking a sense of magic and mystery. Perfect for a spell icon in a high-fantasy setting.