Seven Holy Sword and the Princess of Magic Sword summary:
Apocalypse, a once-in-a-thousand-year catastrophe caused by the "primitive sword". There was a clan who tried to destroy the "Primitive Sword" that day, but the operation failed. Sakuya, the strongest boy in the clan, flies a thousand years later to prevent the next catastrophe, but there is a magical world. Sakuya who can't use magic is looked down on as [incompetent] ...! ?? From "Let's become a novelist", the royal road school fantasy begins where [the strongest swordfighter] saves the world!