Kuro Tobi no Seija: Tsuihou sareta Kaifuku Jutsushi wa, Ariamaru Maryoku de Yami Mahou wo Kiwameru

Russel was a saint who was an expert in recovery magic. He was in a group with his childhood friends until the rest of the members learned recovery magic. Branded unnecessary and expelled from his group of friends, he meets a mysterious beauty named Sybilla. His infinite magical potential, combined with her guidance, now allow him to reach heights once deemed impossible!

(Source: Overlap, translated)