In a world where bloodline supremacy reigns supreme, magic was the privilege of the nobility. However, with the invasion of demons, the magic of the nobility becomes powerless, and the world heads towards destruction. Humanity’s last hope lies with Colin, the strongest swordsman of slave origin. Just before his death, he obtains the “Forbidden Book,” which allows anyone to learn magic. When he awakens, he finds himself five years in the past, as a boy. This time, to change the future for good, Colin will rule the world as a “Magic Swordsman,” possessing both sword and magic, and save humanity from the demons!