The underground ossuary in "Metaphorical Fantasy: ReFantazio" is the dungeon of Regalis Cathedral. After you clear this dungeon, you will find two locked doors, and you want to open these two If you open the door, you can go out and continue through the plot, and then go to Maltila. Finally, you will receive a mission that will bring you back here.
How to open the door lock of the underground city of the Metaphorical Fantasy Cathedral
When you first explore the dungeon, there is no way to open those locked doors. Defeat the main boss in this dungeon and continue the story until you reach the second town - Maltira. After completing several bounties in July, you can talk to the Recruitment Dispatcher and he will mention a noble in Sol Lemo Street. This noble has requested that you retrieve an item from the Cathedral Dungeon of Regalis. This marks your second visit to the tomb.
At the entrance to the dungeon, you can also receive tasks from nervous soldiers.
When you enter the dungeon, you will find that the straight road ahead is blocked by soldiers. They tell you that the cathedral is under maintenance. You'll also notice that the previously locked gate is now open, allowing you to search for items and go left, heading to the new area you were tasked with. The closest items you can pick up are sacred urns and rusty trinkets. Don't worry about the other locked gate on the right; you can explore and detour to reach that part of the dungeon.
