A mermaid and a corsair

A corsair was commissioned to kidnap a princess of the sea. But it turned out that she kidnapped him. Now he is a prisoner of an underwater kingdom filled with monsters, water dragons and sea fairies. But his worst challenge is his love for a mermaid he had to deliver to the wizard king of Opal for some reason. The task could still be accomplished, but which is more important: pirate duty or magical love?