Help! Trapped by a Two-Headed Snake Demon

[Master and apprentice + yandere + paranoid + vest + pure love] [The heroine Su Daiyue is the leader of the No. 1 Killer Organization, the most beautiful woman on the Baixiao Hall's peerless list, has great martial arts skills and conquers the country] [The male protagonist Mu Ting'an is a two-headed snake demon who purely loves warriors but only loves the female protagonist. He is a bit sickly] Three hundred years ago, the two-headed snake demon Mu Qingfeng, who was the Demon Lord, disappeared after sealing away many evil-doing monsters. Everyone in the world said that Mu Qingfeng ascended to immortality. Three hundred years later, the story happened to Su Daiyue, the young master of the Rakshasa Hall, the first sect of the Demon Religion. He was a man of great martial arts and aloofness. The story unfolded because of the three-hundred-year agreement between the Rakshasa Hall and Jingguo... Su Daiyue looked at the crazy Mu Ting'an in front of her: "I don't like you, don't you understand?" Mu Ting'an hugged Su Daiyue directly: "There are so many people in the world who are in love with each other. My love for you is enough!" Su Daiyue looked at the unreasonable Mu Ting'an: "It's simply unreasonable." Note: [In the early stage, the heroine was cold and beautiful, with strong martial arts skills, but in the later stage, due to some reasons, she was soft and beautiful, but Dai Yue is beautiful no matter what.] Forgive my heroine's head. [The male protagonist is an obedient puppy in the early stage, and becomes a yandere snake in the later stage, becoming a pure love warrior]