Level 1 no Saikyou Kenja: Noroi de Saikakyuu Mahou shika Tsukaenai kedo, Kami no Kanchigai de Mugen no Maryoku wo Te ni Ire Saikyou ni

One day, Haruto Saijou was forcefully transmigrated and cursed by a god from another world. A world of swords and magic. In this world you get stronger by increasing your battle levels. But due to a curse, Haruto is unable to gain levels. However, due to a mistake by the evil god, Haruto was able to obtain an inexhaustible supply of magic...

(Source: Shousetsuka ni Narou, translated)