Express [{argument name="subject" default="a powerful AI builder"}] in a graffiti sketch style, presenting an overall visual effect of rapid sketching, free transformation, improvised hand-drawing, and draft-like qualities. Lines are casual, exaggerated, varied in thickness, slightly messy but rhythmic and expressive, emphasizing generalization, exaggeration, fun, and spontaneity rather than rigorous realism or fine detail. Colors use rough, dry-brush block expressions, retaining uneven smears, brush marks, flying whites, and overlapping feelings. Colors automatically adapt to the [theme/subject], but the overall expression remains graffiti-like, sketch-like, and generalized. No transparent watercolor smudging, no delicate watercolor transitions, no paper textures, no soft atomization, and no dreamlike quality. The background is mainly white space, remaining simple, relaxed, unfinished, and design-oriented. A small amount of auxiliary symbols, arrows, marks, circles, repeated lines, handwritten text, or other graffiti elements can be added to enhance the sketchbook or essay-like visual language, but should not be too crowded or destroy the subject and atmosphere of the white space. The image content does not need to be written in advance; the [{argument name="subject" default="a powerful AI builder"}] will automatically deduce and generate the most suitable main image, actions, related elements, symbols, or simplified scenes. The whole maintains a unified graffiti sketch style and exaggerated generalized expression, avoiding complex realistic backgrounds and over-elaboration. Naturally add a unique signature "{argument name="signature" default="BlanPlan"}" as part of the image, placed discreetly but clearly in the lower-left, lower-right, or near the title. The style should be unified with the overall layout, like an artist's signature or design inscription; the signature font should be refined, restrained, and high-end, not too large, not destructive to the main composition, and not appearing abrupt or cheap.