Demon Slayer: The Moonlight and the One Who Appears from Nowhere Can't Both Be Had

*The main story is complete. After Rong Ji became a demon, she dared to ask Muzan for more blood and wasn't killed for it. After that, Rong Ji's standing among the demons changed. Just as everyone thought the two of them were a couple, she walked into the sunlight and met her death. "Since it was Chun's request, I will serve you faithfully, Lord Muzan." Rong Ji knelt at his side, bowed her head, and bared her pale neck, offering her loyalty to that lord. *She is a demon. *The protagonist is chaotic neutral. *Contains original worldbuilding! It's not tragic (probably). Theme: From knowing nothing of love to dying in a daze