Majo no Danna no Tsukurikata

From Square Enix: To create a successor for the powerful witch who guards the seal of the Lord of the Underworld, the witches seek the "strongest husband". Ladi, a witch who cannot use magic, meets a boy named Otto, drawn to his swordsmanship? A battle fantasy about a bottom-tier witch and a low-ranking gladiator raising the "strongest husband".