Alter Ego Villainous

Marie Trenton, the cheery and optimistic first daughter of the most powerful Duke in the world has to take the new 'Alter Ego' serum made at the mage tower, prescribed to each noble child sometime in the age of 16.
Now, everyone loved her and some didn't, but it was no surprise that everyone was surprised when they saw her new personality for the three days it took effect.

The old: "Oh no you are completely fine! It was my fault I positioned my body towards you!"

Replaced with the new: "Spare me the words you imbecile, now either pay me the amount this dress cost or never let me see your filthy body again."

For three days at the noble outing. Let's just say, there are definitely new aspects to her life for these few days.

DISCLAIMER: This is VERY manhwa (reincarnated villainous troupe) like so that's why the characters in here aren't literally historical fiction but it's kinda like those novels that the protagonist isekais into from truck-kun haha, the only difference is that the MC is the MC and she didn't come from any place other than this world I created!
I'm an amateur writer too so please don't hate on me too bad Im writing this for my own entertainment and for people who want it ;)
Also HAHA THE COVER IS A PIC OF MY STUFFED ANIMAL IDK WHAT TO DO BYE