In the End, the Villain Does Not Understand Feelings

Years of planning, shattered in the past, and then accidentally learned that he was just the so-called... final boss?
Looking at himself, and at the 'protagonist' opposite, Xia Yin silently drew out his knife.
"Come on, lie down."
PS: This book is also known as "Love and Kill Each Other Every Day", "I Can't Be Turned into an Enemy as a Wife", and "Do you Like the Ultimate Villain as a Wife?" 》