A dynamic full-body scene of a devoted Sister of Battle set in an action-packed moment. She stands gracefully in front of a magnificent stained glass window, embodying beauty and strength. Her armor, styled after a sci-fi nun suit, reflects the intricate design elements of Warhammer 40k. Her face is symmetrical, with reflective eyes and dark, expressive eyebrows highlighted by mascara. The scene is set within marble walls, with visible dust particles adding depth to the atmosphere. The lighting is dramatic with chiaroscuro effects and rim lighting, casting a majestic glow from above. The artwork, influenced by professional impressionism oil painting styles of Waterhouse, John Constable, and others, is richly intricate and high in detail. The depiction should avoid common artistic errors like extra limbs or poorly rendered features, focusing on a clean, precise execution trending on platforms like ArtStation and CGSociety. The composition conveys a sense of epic scale and grandeur, capturing the heroic essence of a Sister of Battle within the fantastical universe she inhabits.