The Crystal Palace Plan of the Sinner Lord

Caesar is a pioneer noble of the demon clan. To put it bluntly, he is a more glorious cannon fodder, fighting on the front line between the demon clan and the human imperial army.
However, he is determined to become the Demon King!
However, he was severely injured during his first raid on a village.
Facing the inevitable end of being swept away by adventurers, he accidentally swallowed a soul from another world and inherited the system:
[Charming Aura] The target will automatically think about what you say and come up with ideas that are helpful for the strategy.
[Curse of Original Sin] You can inspire the evil thoughts in human nature and make people face their inner hypocrisy.
[Eye of Truth] You can see the information panel of the strategy target and related targets.
[It is detected that there is a captureable target around you, and the capture mission is triggered! You can get rewards by capturing! ]
With the help of these magical abilities and rewards, the princess traveling to foreign countries, the Vatican envoy patrolling the border, the tsundere fox-eared girl, the wizard girl who strayed into the territory, the bad-tempered brave girl... all became Caesar's possessions, and unknowingly, his territory where he kept his beauties gradually became what humans called the Demon King's territory!
……
Caesar: "What? You are the hero's fiancée? Great, the territory needs people like you!"