Kami no Tsukai no Shoujo wa Hatsukoi no Shougun ni Subete wo Sasagu

Lily is an orphan girl with the special ability to wield sacred artifacts. General Hughes, her secret crush, proposes marriage to her. However, the main purpose of the marriage is intended to harness Lily's power in a tense situation with another country, Hughes thought of Lily more like a little sister....... Lily, who knows about Hughes' horrific past, realizes that she is being used, But she accepts his proposal so she can fight by his side. (Source: Comic Ride Ivy, translated)