When the Witch King of Angmar died, it was probably the smartest thing that he ever did. Which was saying quite a bit, given that he was immortal and all of that, how no man could kill him. It was a woman that had slain him, with a sword of blued steel, common among men. It was not anything special, no Excalibur or fabled blade. She, guised in the garb of a man at war, slew him over the fallen body of her uncle, the King Théoden of Rohan, realm of horses and men just as wild and free as the majestic beasts they rode.
As he burned from the inside out, the black magic that allowed him existence tearing him apart into nothingness, the darkness that the Witch King was smiled a small sort of smile, the kind that one gives when they know a secret. He had been so clever in creating his identity. He had made himself appear invincible, undefeatable, indestructible, everlasting demise and darkness. No man could kill him. Oh, how sly and cunning he had been when he formed a slight loophole in the deal he had forged with Death, so sly that it made him grin.
He had known for a long time that Sauron of the One Ring would come to the gateway of Hel to ask of his services. Of course the Witch King accepted the mighty lord's offer with open arms. He had it all planned out from the beginning of time. He would be the villain of the stories forevermore unless there was some chance for him to change, to become different, to grow and become better than he had been. So he died. After many ages into the past of plotting and killing and scheming, he was finally able to carry out his ultimate plan.
The Witch King was the offspring of dark tales told by flickering candlelight on stormy nights and the hot ashes and flaming coals of cities burning beneath blood moons, of moonlight on dark water, and the screams of children. Of these things he was composed, and they were him, and thus he was formed from the fear of mankind. He was purely black and of the void, a creature of impenetrable darkness, and his mere presence instilled terror in all that gazed upon his shaded form. None had ever looked upon him without fear, and when Eowyn, sister-daughter of Théoden, gazed hard into the emptiness behind his iron mask, he knew that she was the one. She was the maiden that would kill him. He could see no fear of Death in her eyes, none whatsoever. In his final moments, he felt a peace fall over him, even as her sword pierced through the cursed iron of his helm and the dark spirits holding his form together screamed at their release.
He buckled down to his knees, falling into the grasses of the Fields of Pelennor stained with the blood of armies, watching as Eowyn was thrown back from him by the Black Touch of his spirits, seeing the body of his winged serpent steed, the carcass of Théoden barely breathing, the sky a burning grey color. He looked up at the heavily clouded sky, the air dusty brown from the dirt sent up by the horses' hooves, outlining the gore of the battlefield. Thusly he cast his past the clouds to the Dark Tower that resided in Mordor, the land of darkness, past the barren wasteland, and to the flaming Eye of Sauron. His fading spirit managed one last grin and two last words.
"I…win."