I'm the Heiress of a Villainous Household

Ten years after being reincarnated as an extra in a novel. The day my grandfather, the owner of the house where I grew up, died, of the infamous ducal family of Blasco. "His Excellency the Grand Duke bequeathed all his assets to the girl Katisha." "His Highness the Grand Duke." So my grandfather is the Duke of Blasco? I am struck by the enormity of the inheritance, but it is impossible for "the" Duke of Blasko to leave me alone, even because we are related! "No, thanks..." "Cash, excluding inheritance tax and personal deposits at the central bank. You can keep everything else in Blasco's name." "I want!!!"