Keizoku wa Maryoku Nari

After long and hard training with magic, Leon learns that his unique magic of Creation is garbage! And yet, because of his incredible amount of mana and unimaginable luck, Leon can use his useless magic to create all sorts of things: for example, the magical sword-masochist! Moreover, he becomes a close friend of Princess Cherry and the granddaughter of the holy maiden, Riana, after revealing his abilities to them!