My Sister Didn't Regress

※Please note that this work and its side stories contain scenes that may be perceived as coercive. Romance fantasy novel <The Regressed Princess's Revenge is Cruel and Beautiful>. I was reborn as Nigel Cordis, the younger brother of Evelyn, the princess and protagonist of that novel I read in my past life. But…… "Sister, do you really not remember anything... about him?" Duke Valencia, Oscar. Who is he? The head of the empire's sole ducal family, recognized for their merit in founding the nation. And, a man harboring immense hatred and ambition toward the imperial family. The princess is killed by that Oscar, and to take revenge on him, she regresses to the present time. However, th...