There are other comments here that explain exactly what happens very well but to roughly sum it up: if I’m correct then rez (or whatever her name is) will only really start to have her punishment arc in the side stories, the actual ending is more focused on our FL and ML’s relationship where they get married and move away from the capital to live in the place ML got from his parents instead of being the heir (we saw in a recent chapter) and stuff like that.
Anyways, Rez married clif and makes him sign a contract to protect her and never divorce her (or smt like that). After marriage Rez starts to spend a tooon of money on clothes, jewelry and the likes which causes her to fight with clif. Rez is mad she’s not the mc anymore and gets no attention from clif so she starts to get it from other men at parties she’s always holding and during that time she also tries getting close to the prince, or smt happens where she’s involved with the prince and it makes the emperor think the dukes family is trying to overthrow the royal family. Emperor scolds duke who then scolds Rez which makes Rez want to follow the og storyline to try and become mc again. She goes to an auction to find the emperors nephew but ends up bringing back a random kid and copies the nephews birthmark and teaches him etiquette to try and trick them. They aren’t fooled so she’s now being charged as a criminal. There are some issues where cliff is suck trying to save her because of the contract but eventually gets the contract broken so he can divorce her (don’t remember why it’s broken but it just is lol). Fl and ml are coming back to the capital and run into the real nephew and bring him with them, and when the nephews mom (emperors sister) sees him, she knows right away it’s her son. Fl basically a hero now so emperor gives her the right to choose what happens to Rez and the fl decided to spare her life and to send her to a monastery instead of being executed. So in the end clif apologized to fl for all the stuff he ever did to her and she accepts and she and the ml even tell him he should remarry and find true love, and even though he was reluctant at first he does meet a viscounts daughter who truly loves him and he loved her too so he married her.
That’s basically what happened without getting too into the details and mostly cus I forgot them lolol. If you want more detailed stuff I just suggest looking at other ppls comments cus they explain better than me tbh.
After reading spoilers, I’m obviously still going to read the story cus the ending isn’t horrible, I just wished that the villainess got a bigger punishment. Like I understand that the mc doesn’t want to be evil like rize or whatever her name is, but to spare her life and only send her to a monastery? It’s kinda a slap to the face of all the innocent girls she literally murdered- if not on her own account, I wouldn’t let rize get executed for the sakes of those she wrongfully killed… it’s still a decent ending I guess, she got punished thankfully but it’s just a liiittle disappointment is all. If the author changes the ending to let her get executed for the manhwa then It’d be perfect imo.