Migawari de Endan ni Sanka Shita Gumai no Watashi, Ringoku no Ouji-sama ni Misomeraremashita

In every generation, only a single saint is destined to be born, yet fate defied tradition when Hestia and Astrea arrived into the world as twins. Despite their shared bloodline, their abilities could not be more different. Hestia, the elder sister, possesses the miraculous powers expected of a holy maiden, while Astrea, the younger twin, lacks any such gifts. Branded as incompetent by those around her, Astrea endures a life overshadowed by her sister's brilliance and subjected to relentless scorn. Hestia’s arrogance knows no bounds, and she exploits her younger sister without hesitation. When marriage proposals arise, the elder twin forces Astrea to attend in her place as a mere substitute, treating her as nothing more than a convenient pawn. However, this cruel arrangement leads to an entirely unforeseen encounter. At the meeting, Astrea comes face-to-face with Silvert, the second prince of a neighboring kingdom. Rather than the humiliation she anticipated, the unexpected happens, and the two find themselves formally engaged, setting the stage for a destiny that could finally change everything for the overlooked younger sister.