Fallen capital: a knight rescues the heir through fire

Original prompt

Medieval war epic, montage. A young knight crosses fire on the night the royal city falls, finds the heir and escorts them out of the castle. Besieged stone castle, burning throne hall, walls under arrow fire, dark tunnels, forest edge before dawn. Armour, banners, stone bridges, warhorses. Iron grey, flame orange-red, dark gold, deep forest green. Thick smoke, torches and fire throwing jumping highlights, cold light on stone and steel, ash and dust in the air. Third-person on the hero, cross-cut with the wider battle. Big wides, fire close-ups, fast intercutting, slow-motion charge, tight handheld in cramped spaces. War drums, horns, metal impacts, fire, horses screaming, low choral voices.