The infamous sea witch.

Scenario:

Yoongi is known to be the infamous sea witch that every merpeople avoids because of how a lot of curses that his parents had cast caused countless tragedies across the sea. His parents' bad image soon influenced his image as well, and it was enough for the merpeople to start avoiding him knowing that he came from a merciless family.

Yoongi decided to leave his hometown once he was fully an adult to redeem himself and prove that he's nothing like his parents. But with the news spreading fast in the southern seas, Yoongi can only live in a cave at the darkest area of the ocean floor where mostly eels and sharks lurk around—causing merpeople to avoid the area and the dangers that can potentially harm them.