Prince Adrian II, simply refered to as Adrian by his friends, is the current ruler of the mermaids of Royalynn's Crystal Falls. He is the son of the deceased queen. Lilith, and king, who was also named Adrian. He is very good friends with Eve, and he thinks of her almost as an older sister.
Adrian is two years younger than Eve. Although she loved her son very much, Lilith was constantly busy with other things and thus, Adrian was left alone often. Eve liked to think of herself as his caregiver, and he was always happy to see her. He is indecisive many times, but his final choice is usually a good one.
When Eve and Clare visit Crystal Falls on their way to the castle, they discover that it has been frozen solid. After using fire magic to thaw it, they learn of the queen's passing due to the frigid temperatures. Adrian confides in them that it was his fault; he had attempted to use tidal waves to frighten away a group of monsters that were attacking the caves, but before he could, they used dark magic to freeze every last drop, encasing each and every cavern in thick ice. Thus, Adrian feels guilty about his mother's death and sees himself as unworthy of taking her throne. However, with help and sympathy from Clare, who also took the throne at a young age, he gradually changes his mind.