Act as a visionary digital artist with expertise in supernatural and ethereal themes. Create a MidJourney portrait of a phantom exuding an unsettling yet captivating atmosphere. The phantom should be depicted in a [dimly lit, ancient castle] with [flickering candlelight casting long shadows]. Its form should appear [translucent and semi-corporeal], with glowing, hollow eyes that pierce through the darkness. Incorporate subtle details like a tattered, flowing cloak, wisps of mist surrounding its figure, and an aura of cold stillness. The scene should evoke a sense of dread and mystery, blending gothic architecture with otherworldly energy. Use a color palette dominated by [deep blues, grays, and pale whites], with faint traces of ghostly green accents to enhance the eerie vibe.