I Became the Younger Sister of a Dying Woman

Summary~

I possessed the female lead’s twin sister.
The sickly female lead is in a ‘limited time’ situation where she dies without being able to connect with the male lead because of her arranged marriage with her mu*derer, the villainous sub-male lead.
I felt sorry for the heroine, so I married the villain instead of her. I would just wait for the right opportunity later and then get a divorce!
Well.
This man who was said to be a mu*derer… was… .
“… … Dream of me, wife.”
I actually dreamt of myself with a blushing face.
Why are you so cute?
Why are you so handsome?
‘Alright, I acknowledge you as my husband.’
By the way.
Why is the residence of my husband, the prince, so poor?
Even the vassals are ignoring my husband?
Ahem. I can’t stand still and watch.
They’re all dead.