In her previous life she was killed by her brother the day of her wedding. This then started a war between her husband and brothers countries. She didn’t just pass away, she was a lingering spirit that over watched everything unfold. Her husband went mad and massacred the whole country.
When she was reincarnated she did things differently, she ignored her older brother that killed her in her previous life and she started manifesting her magic awakening. When she turned 20, her house was ready to wed her to her husband. Only this time she was hoping to do things differently, act cold, and play it smart.
When she was at the alter, it seemed that it was the day she fell in love. They have intense chemistry. He does things for her that she doesn’t understand. He didn’t behave this way in her previous life, so she thought the worst in him. She only saw the madness and the massacre he did. He only went mad because of how in love he was with her, his background isn’t really revealed so we don’t know to what a veal he knows about his wife.
My Sweet Enemy, Thy Name is Husband