boss fight, Deacons of the Deep, Dark Souls 3, cathedral setting, eerie ambient lighting, gothic architecture, multiple robed figures, glowing red eyes, central massive deacon, casting spells, ethereal blue flames, dark mist, cursed artifacts, high contrast shadows, dynamic action poses, decrepit stone statues, stained glass windows, flickering candlelight, ominous choir music atmosphere, 3/4 view, detailed textures, atmospheric perspective, dramatic composition.