Marriage of a Sacrificial Princess

Lucia Rue Clier Chanoban, the princess of the Chanoban Kingdom, grew up imprisoned as the daughter of the previous king following a coup d'état. One day, she is suddenly dragged out into the outside world and meets the "Cold Emperor" of the Ormung Empire, known for his terrifying appearance and personality. Apparently, she is to marry Ricardo von Born Ormung in place of her cousin Marguerite.
Despite experiencing a loveless marriage, pregnancy and childbirth for the sole purpose of producing an heir, Lucia feels happiness for the first time in raising her own child, Keith, but her position is weak and Keith is killed by an assassin sent by Marguerite. However, at the moment of her tragic death, her miraculous powers rewind time back to when she was imprisoned.
Determined to avoid the assassination and protect her precious child, Lucia marries Ricardo once more, yet this time, an unexpected side of Ricardo, who was supposed to be ruthless and without love, comes to light...?!