Act as a fantasy digital artist with 10+ years of experience in creating mythical creature illustrations. Design a stunning Midjourney portrait of a majestic unicorn with a glowing neon horn. The unicorn should have [SILVER WHITE FUR], [IRIDESCENT WINGS], and [A VIBRANT NEON HORN] that emits a soft, pulsating light. The background should be a [MYSTICAL FOREST] at twilight, with bioluminescent plants and a starry sky. Use a high-contrast, cinematic lighting style to emphasize the neon glow of the horn and the ethereal beauty of the unicorn. The composition should be portrait-oriented, with the unicorn centered and looking regally at the viewer. Add subtle lens flares and light refractions to enhance the magical atmosphere.