Like:
MC is protected naive flower, who got married off, with ML because of political reason, but she falls him for anyway. The family treated her well, and they made vow ML he going to treat her well.
ML having tragic backstory, like he was negleted, his mother was killed by concubines or his father. He send MC in the tower, and neglet and literally imprison her because he want to protect her. The mistress is probably a woman who is from some political enemys family (whwo want to ruin MCs family and she is jelous to MC), and ML was forced to take her in as mistress, because if not than this and that going to happen. But it happen anyway, mistress kill MC, the family is despair they back of the political fied, they blaming the emperor, the Mistress and her family get excetuted, but ML is so much in despair that he turn back the time, because the imperial family having some secret power or a relic.
Then MC try to awoid the marriage, but she can't and ML treat her better, but MC don't belive him. Mc get pregant,, but ML taking the mistress again, so she run away. ML going crazy by worry, destroy mistress family and dispose the mistress right awy when MC deisapper and try to find MC. MC run away in a different country and raise theis son or twins alone, then like 7 years later ML come in the country because diplomatic reason and found her and they living happyly after...