Boku no Kawaii Musume wa Futago no Kenja: Tokugi ga Debuff no Teihen Kuro Madoushi, Sodateta Futago no Musume ga S-Rank no Daikenja ni Natte Shimau

Elcan, a dark mage specializing in debuffs, is expelled from his adventuring party due to his perceived lack of offensive magical talent. While wandering the streets, he discovers twin girls abandoned by their parents. Resolving that although he failed as a dark mage, he can still provide these children with a better life, he retires from adventuring to raise them as his own daughters. He names the twins Corona and Selena, teaching them black magic and enrolling them in a prestigious magical academy. Upon completing their studies, the sisters return home with astonishing news: they have both achieved S-Rank Sage status. Now, they wish to form a new adventuring party with their father, marking the beginning of a fresh journey for Elcan and his daughters.