A Proxy Bride for a Marquis's House: The Villainous Powerbroker Wants Me Dead Every Night

I transmigrated into a book as a vicious supporting female character, forced to take my legitimate elder sister’s place and marry the biggest villain in the whole story. On our wedding night, he squeezed my throat and asked, “Who do you belong to?” I trembled. “Y-you…” Inside, though, I was ranting like crazy: In the original story, you kill my whole family. Now I just want to give up and wait to die, so why are you still insisting I become empress?