Create an illustration featuring the shadow cat and its cosmic guide standing before an ethereal observatory in black and white, situated within the dream realm. The observatory should radiate a captivating glow, representing the journey's culmination. The visual should convey a sense of farewell and ongoing connection, as the ethereal aspects blend harmoniously with the tangible world. Employ a continuous line drawing style with intricate details, maintaining a realistic touch without additional shading or colors. This approach allows colorists to engage in the contemplative process of hand-coloring and reflect upon the seamless fusion of the dream and reality.