After I was sacrificed to the evil dragon, my brothers regretted it

Synopsis of After I was sacrificed to the evil dragon, my brothers regretted it: Princess Mira of the Silver Moon Kingdom was rescued from the ruins of war by the royal family as a child and raised under their constant protection for seventeen years. However, when Serla—who claimed to be her "biological sister" —returned to the royal household, everything changed: her family began to neglect her, misunderstood her, and even repeatedly pushed her toward the abyss. On the surface, Serla appeared gentle and kind; beneath this facade, however, she was ruthless and cruel—she stole Mira's music box, her evening gown, and her room, and even framed and accused her, leaving her three elder brothers and parents utterly disillusioned with Mira. Mira endured all of this in silence, secretly entering into a covenant with the Dragon Clan—sacrificing herself in exchange for a century of peace for the kingdom—and exchanging her heart for that of her second brother, Solin, who suffered from cardiac disease. On her 18th birthday, her family expelled her from the royal palace due to Serla's lies. Without offering any defense, Mira walked alone toward the altar and was consumed by flames, vanishing into nothingness. Only when the truth was finally revealed did her family, consumed by endless remorse, forever lose the girl who truly loved them.