The female lead is a killer, the male lead likes the female lead, but the male lead finally dies for the female lead's anime

The female lead is a killer, the male lead likes the female lead, but the male lead dies in the end. For the sake of the female lead's animation, you can refer to the following types of novels: 1 "Black Fire": The story is about the female protagonist Black Fire is a professional killer and the male protagonist Lu Wangshu met and fell in love, but Lu Wangshu's identity is a policeman. There has always been a conflict between the two. In a mission, the black fire seed sacrificed itself to protect Lu Wangshu and eventually became his substitute. 2."My Boyfriend Is a Ghost": The story of the female lead, Bai Xiaochun, a professional assassin, who meets the male lead, Chen Mingsheng, and falls in love with him. However, Chen Mingsheng's true identity was a cursed ghost who had been searching for his family. Chen Mingsheng had sacrificed himself on a mission to protect Bai Xiaochun, but Bai Xiaochun had eventually discovered the whereabouts of Chen Mingsheng's family. 3 " Assassin Wu Liuqi ": It tells the story of the female protagonist Wu Liuqi, an assassin. She meets the male protagonist Ah Qi and falls in love with him. However, Seven's real identity was a Qing Dynasty guard who sacrificed himself to protect Wu Liuqi. Wu Liuqi eventually became Seven's substitute and continued his assassin career.