Saikyou Kensei no Mahou Shugyou: Level 99 no Status wo Tamotta Mama Level 1 kara Yarinaosu

Ragna, "Master of Sword", used to be the strongest swordsman. He ventured alone into the mysterious Heavenfell Tower and reached where no man had stepped before, the seventh floor... only to find the limit of his growth. However, his story is far from over. He gets reincarnated and returns to level 1...while keeping all of his level 99 stats?! (Source: MangaUP!)