In standard fantasy, the "yuusha" (hero) is a righteous figure. But in dark subversions, the hero becomes the ultimate betrayer — using his status, power, or charisma to steal the love interests of the real protagonist (often a former ally, childhood friend, or another hero candidate).
Everyone Was Taken by the Hero, but I Won't Give Up. I'll Definitely Win in the End yuusha ni minna netoraretakedo akiramezu ni tatakao raw free