The Silver-Haired Crown Prince’s Gifted Consort

He is the Demon King in the eyes of the world: cruel and bloodthirsty, ruthless in battle, and once responsible for massacres that left cities razed, kingdoms destroyed, and rivers of blood flowing. She is a useless young lady in everyone's eyes: timid and weak, someone anyone can bully. When he meets her, the merciless Demon Lord transforms into an adorable young man, acting sweet and cute all day and using every trick in the book to cling to her. The girl, who can't resist anything cute, is completely overwhelmed. Who can tell her why the bloodthirsty Crown Prince is such an adorable young man in private? When an adorable young man meets a cunning girl, when the greatest modern assassin meets the greatest ancient assassin, who is the true king?!