Kami ookami denka no saiai-hi (dakedo watashi, honmono no tsugai jaarimasen!)

My reincarnation destination is the villain princess who becomes obsessed with the “King‑Wolf Hero” and gets killed!? Luna, the youngest princess of a small kingdom, realizes she is now living inside a novel she read in her previous life. In that story, Rudolf, the King‑Wolf Hero, is a crown prince who cannot find his fated mate, and the only way to stop his rampage is through love—yet the “true heroine” who should fill that role dies, and princesses are murdered again and again. Fated to be hated by Rudolf, Luna is ordered by him to “act as a fake mate”… only to find herself loved to the point of drowning in his affection. Can a pretend bond overturn a doomed fate and rewrite the story meant for the true mate? Source: utoon.net