Hard Mode na Akuyaku Reijou ni Tensei Shimashita ga Ikinobite Sekai wo Sukuimasu!

The story follows the protagonist, who is reincarnated as Liliana, a character from a girls' game he created. Liliana is a villainous young lady, and as her favorability rating with the heroine increases in the game, she dies in an accident or from illness, earning her the nickname "hard mode young lady." In order to avoid such a life of sudden death, he must use his knowledge of the original work to his advantage.

(Source: Natalie, translated)

Note: Includes two extra chapters.