The Emperor That Was: Vision, Power, Purpose

Create a photorealistic, sepia-toned mural depicting the Emperor of Mankind leading his Thunder Warriors during the Unification Wars on a battle-scarred Terra. The Emperor, tall and radiating light, with long black hair and golden armor, stands on the left, gazing stoically at his Thunder Warriors. On the right, legions of Thunder Warriors in early power armor, alongside saints and legendary warriors, kneel in homage. The background features dark, turbulent thunderclouds. The mural should appear cracked, aged, and like a forgotten ruin, evoking a sense of fragile, ancient memory. The style should be reminiscent of Warhammer 40,000 art, specifically resembling a Roman mural constructed from small, polished mosaic tiles, with the individual tiles clearly visible and irregular shapes. Capture the mural's full length in a wide-angle view. Maintain a grimdark aesthetic.