Summoned the Succubus, but My Sister-In-Law Came

This is a land that was once visited by darkness. People of darkness such as vampires, werewolves, and demons are thriving on the earth. The human race was reduced to blood food, struggling to move forward in the long dark age. Until four thousand years ago, a glimmer of light was finally seen. In the Battle of Dawn, the human race broke their shackles and gained freedom and light. The world is divided into two, the two camps of light and darkness are in opposition, and they are constantly conquering each other. Bai Huan traveled through time and was reborn in the body of a young man on the border of the empire. He has a twin brother, who is the favored son of heaven and plans to sacrifice his biological brother to summon the devil. Bai Huan killed his brother but failed to stop the summoning ceremony. As the crimson light flows, the devil descends. She has dark and deep membrane wings, and... A tail with love! This is actually a succubus! After seeing the familiar face of Succubus, Bai Huan decided that he would replace his brother and inherit everything from him.