Dark Fantasy Samurai Battlefield

A dark fantasy anime illustration of a lone swordsman on a desolate battlefield under a giant {argument name="moon color" default="blood-red"} moon. The character has {argument name="character hair" default="long dark hair in a messy high ponytail"}, glowing red eyes, and wears tattered black traditional clothing while holding a {argument name="weapon" default="katana"} angled downwards. In the background, a {argument name="background structure" default="ruined Japanese castle"} looms amidst dark, swirling clouds. The scene includes 3 prominent tattered banners with Japanese kanji planted among shadowy debris. The lighting is cinematic and ominous, utilizing a color palette of {argument name="color palette" default="deep blacks and intense crimson reds"}.