To Save Seven Villainesses, I Went Full Harem!

I found myself in a novel — "Tianyuan Continent: I Alone Am Supreme," also referred to as "My Seven Wives Are All Villainesses." I became the expendable antagonist destined to meet my end in just three days! Fortunately, I possess a system — and my objective is to rescue the world. If all seven heroines succumb to darkness, the world will face destruction. Therefore… I must save them through love!