Ok, I expected something better, but this is so overdramatic like it's written by an edgy teen. I just about rolled my eyes 5 times just from reading a spoiler. I can't imagine what will happen if I read the actual story. I'm so done with MC's who can't take care of themselves.
Wow, but this emperor is a piece of gem. He left two children to die without a care, even when both of them were the children of women he supposedly doted on. Even if MC isn't related to him, if he loved her mother so much, after he led the mother to her death in the harem, wouldn't he feel the slightest guilt toward the only left kin of that woman. The emperor is a true scum and if anyone deserves revenge, it's him and his harem of vicious bitches.
Anyway, I don't pity the MC, just the original daughter. The MC had all the necessary cheats in order to lead a good life in her first (after transmigration) life. She met a martial arts master who took her out of the palace, she had a space where she had stored stuff from the modern world. Why live her life for some dude like an idiot. She could've explored the world, gone on adventures, live the MC life. Instead, she slaved under a man hahaha. Serves her right, this idiot.
As for the ML... He's the type to remember a good deed done to him till death. Because he faced so much cruelty and betrayal, this one act of kindness was enough for him to treasure. He wouldn't care if the person who was kind to him was a two-faced bitch or if she did it for a benefit. He obviously didn't love her (since he could bear with her being with another man), but he was grateful to her and was twisted enough to be numb toward torture and murder. Don't take this as defending this psycho, this is just his character setting. Why would he care that our MC is the MC, why should he spare her at all, when she's no one to him. In the second chance of this useless idiot MC, since she was kind to him first, he immediately reciprocates even when he's filled with hatred for the others in the palace. Anyway, I hope he gets to kill the emperor brutally, and then massacre all his harem and their child-abusing eunuchs and servants.
As for the MC, I really don't care. She can go die again. Three lives and she still doesn't know how to protect herself and gets poisoned, hahaha... Bitch, you're not suited for the ancient life, just go reincarnate already. She even learns martial arts and is actually better in the second chance, and it still doesn't help her. What kinda villains... Why are MC's so frustrating and wait for the villain to poison and constantly harass them instead of moving preemptively? Why can't she get those rare overpowered poisons and deal with her enemies in a timely manner, but wait for them to do her in first?
Edit: Also, this has a happy end - they get married grandly (though they already have a son, but whatever, I only read the last chapter). The chapter ends with their bridal night and ML professing his love forever. I think he's already an emperor by then.