Create an illustration of Ulquiorra Cifer, a character from the Bleach series. Ulquiorra is an Espada with a cold and calculating presence. His appearance is marked by his pale skin, dark long hair, and his black outfit with an open white jacket, which reveals an elegant design. His hollow mask, which covers part of his face, is a significant feature: it has a distinctive shape resembling a horn. Ulquiorra has an impassive expression, and his eyes, which can show a mix of indifference and mystery, should be clearly visible. Include the number "4" on his hollow mask and uniform to highlight his rank as the Fourth Espada. The background should reflect a dark and oppressive atmosphere, matching his personality and abilities.

verybadimagenegative_v1.3, ng_deepnegative_v1_75t, (ugly face:0.8),cross-eyed,sketches, (worst quality:2), (low quality:2), (normal quality:2), lowres, normal quality, ((monochrome)), ((grayscale)), skin spots, acnes, skin blemishes, bad anatomy, DeepNegative, facing away, tilted head, {Multiple people}, lowres, bad anatomy, bad hands, text, error, missing fingers, extra digit, fewer digits, cropped, worstquality, low quality, normal quality, jpegartifacts, signature, watermark, username, blurry, bad feet, cropped, poorly drawn hands, poorly drawn face, mutation, deformed, worst quality, low quality, normal quality, jpeg artifacts, signature, watermark, extra fingers, fewer digits, extra limbs, extra arms,extra legs, malformed limbs, fused fingers, too many fingers, long neck, cross-eyed,mutated hands, polar lowres, bad body, bad proportions, gross proportions, text, error, missing fingers, missing arms, missing legs, extra digit, extra arms, extra leg, extra foot, ((repeating hair))