Reborn as the Fated Villain

Damien Nightshade, a discarded royal masquerading as a Professor in one of the continent's greatest magic academies, is considered a mid-level boss—one fated to die in every playthrough. Now, I have transmigrated into his body. A game-like world has become my reality, and instead of being its hero, I'm cursed to die a pitiful death as a fated villain. But why should I accept life as a third-rate villain when I can strive to become the unbeatable final boss? Note: This is a villain story—mind the tags!  I have 200k words of pre-written content, so posting will be fast. There is a small romance side plot. No harem.