I like this but I suggest or think manga like it. But make so princess does betray (knowing it she probably didnt in this manga as u see someone else their) but make it real she tells but didnt intend for war. But he stops caring later on just hates her n driven to war against the empire. Make ao instead of some stupid blessing or goddess or g** instead its demon or higher rank then demon like devil. But price is he has demonic blood in him since hes human hes able hide it. Gains demon power and abilities and starts walk of villain [while in eyes of his people hes a hero and eyes of other kingdom's hes ether hero or normal prince who's just going war against a enemy ->empire<- over n over hes more brutal dark in his acts against them while hes seen as hero more n more. Maybe a sibling sees or feels its too much or whatever but he doesnt care maybe had small g** or Avatar or apostles t9 g** to the empire sees consequences trys be all entitled and selfish. I just want a mc be darker hating the girl