Quote Originally Posted by abrojtm View Post
(SPOILER)I don't know how to access the hidden dungeon, but it's not by getting all of the jobs because apparently you get Necromancer by defeating Enuo.
You need to have done a certain event in the third world, then the sea below the mirage village will start to boil at a certain place. Dive with your submarine, enter the sea trench and grab the 3 crystal shards giving you Prophet, Gladiator and Cannoneer. Then beat the game (I think) and enter the door in the upper-left corner. Have fun with a (on the first sight) quite hard new dungeon.