Transmigrating into a Book as the White Moonlight’s Substitute

I woke up to find myself inside a book, as the villain destined to die a gruesome death. The System ordered me to take a sword for the male lead to prove my devotion. I refused on the spot. “Not happening.” I never expected the male lead behind me to suddenly look up. “Wait, you’re not him. Where’s my person? Where did my precious moonlight go?!”