Read the novelupdates spoiler forum for this one long time ago so take this with a grain of salt. Empress (MC) is sickly since childhood and has been in love with ML since they were kids. She can't go out often so she only had the ML to interact with. MCs Father and Brother plot to kill ML via treason or war iirc, but fails and MC thought ML was already dead. Father and Brother arranged a marriage for MC and that's where ML reveals that he's actually still alive and proceeds to kill MCs family in front of her and made her such his d*CK in the church... In front of her dead relatives... Anyway, so MC becomes Empress since everyone else is dead. ML becomes Grand duke and it's obvious he holds the power against her. Atp ML hates MC because he thinks that she's one of the people who framed him up when in reality MC didn't know any of it and was the only one on his side in her family. So ML literally manipulates MC. Then I already forgot the premise of this event, but ML learns the truth and he REGRETS BIG TIME. But MC is having none of it and was like "go crawl like a dog for me then (non verbatim)." Basically, their roles reverse haha, so this situation continues, MC still doesn't forgive ML, and then MC realizes that she's getting sicker by the day since she had always been frail since young. She realizes she needs an heir to continue the bloodline and so she ropes in the ML to make babies with her. But the ML fears that she's die if she gets pregnant and give birth to a baby since she is already getting weaker. So ML secretly takes contraceptive. MC finds out, she gets mad, they snusnu, MC gets pregnant! Then ML gets sick for some reason and a neighboring country is trying to invade the empire so ML has to go to war. That's when MC forgives him I think? Coz she's like "come back alive something." ML comes back alive but still sickly, MC gives birth. Tgt they heal, and that's the end iirc. There're side stories abt their daughter. They were having problems because their young daughter keeps on proposing to almost every handsome men she meets. ML wonders who did she take after and MC thinks "wouldn't it be the you?" But ML goes, "I've never been with anyone else but you tho, so def not me" Then MC realizes that she liked ML as a kid because he is handsome and basically the only one she had interacted with because she couldn't go out due to her frail condition. She thinks that maybe if she had a healthy body as a child, she would've also proposed to every handsome man out there just like what her daughter is doing now .
Anyway, that's all I have, remember to take this with a grain of salt since I've never read the novel itself and has only read the spoilers a long time ago. I also am marinating this until the groveling arc happens hahahahaha
Any spoilers?