My Daddy, the Demon Lord

Kaelan Vaughn, the Demon Lord, is latched onto by Sansa, a three-year-old who calls him 'Daddy.' She forces him to become a full-time dad. When Sansa's identity and Divine Bloodline are exposed, the Emperor Lord of the Celestial Realm attacks. The Demon Realm fights back. The Demon Lord rescues Sansa's mother. The family of three lives happily in the Demon Realm.