space marine, adeptus astartes, warhammer 40k, power armor, blue ultramarines chapter, bolter gun, stoic pose, battle-hardened, sci-fi, futuristic, gothic architecture, cathedral-like spaceship interior, grimdark atmosphere, dynamic lighting, action stance, detailed armor texture, purity seals, imperial insignia, full-body shot, dramatic angle, high contrast lighting, metallic surface, ceramite plating, genetically enhanced soldier, heroic scale, massive pauldrons, chain sword, grim facial expression, space opera setting, monastic warrior monk, eagle emblem, skull motifs.