Master Blacksmith in the Blade of Demon Slayer

Traveling through the world of Demon Slayer Blade, but becoming a swordsman?"Then I must make the strongest sun-wheel knife!"Hammering the iron ingot, but a reminder...[Impurities-1] It was madeinto steel, but a reminder...[Physique +1] It wascast into a weapon, but passed A reminder...[Current weapon sharpness level 1][Forger: Strength +10, Constitution +10, Agility +10, Speed ​​+10][Reward: Sun Breath! ]"Why... I still become the strongest swordsman?"