Transmigrated into the Villainous Big Shot of a Female-Oriented Novel

This is a male-oriented novel, but the protagonist (male) mistakenly switched channels...

Synopsis:

She drank the poisoned wine given by the Regent and watched her former good sister smile triumphantly in the Regent's arms.

Ever since marrying the Regent, they had never shared a bed. From the night of their wedding, she was relegated to the cold palace. It turned out the Regent had only set his sights on her family's wealth.

She was still diligently managing the prince's mansion, never imagining that the Regent had already secretly colluded with her sister.

She was exterminated along with her nine generations of kinsfolk and was bestowed poisoned wine.

Reborn to the age of 16, she only wished for revenge.

System: Your current role is the Regent. You cannot reveal that you have transmigrated, nor can you eliminate the female lead prematurely.