The Emperor and Horus, Before the Fall

Create a photorealistic, wide-angle, grimdark digital painting depicting the Hall of Unity on Terra. The Emperor of Mankind stands before Horus Lupercal, clad in gleaming golden power armor and with long, flowing black hair. Horus, who is a bald man with a gray beard, kneels on one knee before the Emperor. He is also clad in golden armor and wears a red cape, with a white wolf pelt (head on right shoulder) draped over his shoulder. Behind them, display vibrant, long, woven banners representing all twenty Space Marine Legions, showcasing each legion's colors and icons. Dramatic, divine white light streams through tall Gothic windows, illuminating the scene. Emphasize the expressions of unwavering loyalty on Horus' face.