I'm Going to Destroy My Whole Family, and You Regret It?

Traveling to an imaginary world called the Dagan Dynasty, a prince's mansion full of vampires? The Marquis has insulted me because I am of low birth, my mother died for me, and the Marquis wants to take away my family property and kill me? Then start by massacring the Hou Mansion and dominate the entire Dagan Dynasty!