One day, the world suddenly experienced an Apocalypse in every corner, every country and continent faced the Apocalypse in different forms, and various monsters emerged. Eventually, only the ocean was considered a relatively safe place. Everyone decided to sail, and the Era of Sailing began.
Every time someone killed a monster, inside the monster's body, there was a Core that could enhance a person's strength and lifespan. People who were very strong could survive for hundreds of years.
There were a hundred extremely strong Ship Captains who lived for over a hundred years. However, the emergence of various Monster Kings and Queens slowly led to the deaths of the hundred Ship Captains one by one. The Weakest Captain managed to survive for three hundred years and was considered a legend, but eventually, he died. Who would have thought that he would return to one year before the Apocalypse began.