The Tyrant's Replacement Bride

"Yes. I am the replacement. You have been fooled!" To save the world and seek revenge, Isla replaced her elder sister, the Wise Princess Ava Cassia. In order to successfully deceive Sebastian Leodegrance, the Evil Tyrant, she must bury her own identity along with her sister's death. Will Isla succeed in her revenge and destroy Sebastian Leodegrance, or... fall in love with him?