
Spoilers ahead!!!
From what i remember from the novel, it was because Penelope was always there to stop Yvonne with her plans.
1.The game was actually a reality in which Penelope is the last descendant of a great mage which sealed the evil spirits(I forgot the entire detail).
2. The original Yvonne was already dead when she was separated from her brothers during the festival and her body was possessed by an evil spirit (forgot the entire detail, sorry )
3. So the real reason why the og Penelope would torment Yvonne from the game was because she was trying to stop the evil spirit in Yvonne from freeing her kind. But no one would believe her because the male leads, the duke and servants were already hypnotized by evil spirit Yvonne.
4. It was later explained when Penelope found in the hidden ending of the game. It showed that when evil spirit Yvonne married the crown prince she succeeded in freeing her kind.
5. Because of that Vinter made a spell which reversed time.
5.That's why Yvonne said in the newer chapters in why Penelope was so different from before because she wasn't the og Penelope.
6. The evil spirit Yvonne remembered everything that happened.
If I made a mistake with the explanation or if there are other parts which were wrong and missing, feel free to correct me.
Genuine question. Why is pseudo yvonne is out to fuck penelope up? What she after for? Whatever it is, can't she just let penelope be if penelope wants nothing to do with the duke family?