To begin this very lengthy sidequest, head for the Sanctum in Gathelatio. Standing in front of the podium at the far end is none other than Grand Marshal Braev Lee. Now that some form of peace has been attained, Braev issues one final test for his daughter, Edea.
Hiding within Everlast Tower towards the north-east of Eternia is the Grand Marshal’s Sword , while lurking in the basements of Eternian Central Command is the Grand Marshal’s Shield . Depending on Edea’s beliefs, she must head to one of those locations and retrieve the desired item.
Of course, you could be smart and obtain both. In any case, we’ll start with the shield since it’s the easiest. Annoyingly, you can’t land the Rubadub anywhere near Central Command. Instead, make your way to Eternia City via the teleporking pig outside the Gathelatio inn or other means.
From there, exit the city via the west and follow the narrow mountain trail north towards Central Command. Once inside, you’re welcome to set up camp with the Adventurer’s fox, before continuing north-west through the newly open door. Beyond are stairs to the prison.
It’s not often that you purposely try to get into prison, but here you are for Edea’s sake. From the entrance stairs, head directly south, where there’s a chest in the south-east corner containing an Ether . Next, briefly head west along the passage you passed by, then north and west again.
Grab the shiny Phoenix Down at the end of the southward passage. Afterwards, head back around and follow the unexplored passage to the south. As you travel west, halfway along there’s a passage leading north with lanterns on the sides of the entrance–boldly go forth.
Just after passing the solitary lantern on the corner, go west to discover a chest below with 5000 pg inside. From here, carry on north along the previous passage, stopping for another detour to retrieve a chest to the north east containing a pair of Hermes Sandals .
Once you’ve tried on your new shoes or otherwise, stick to the central passageway as it goes west. Upon reaching the north-west corner, head south for a chest with a X-Potion inside. Finally, take the southward path on the right to reach the stairs.
Phew, you’ve escaped the labyrinth and reached the actual prison. If you check your map, you’ll notice a blue exclamation mark, which of course highlights the location of the Grand Marshal’s Shield. Rather than head straight for it, you should search around for the inevitable treasures.
From the stairs, head for the bottom-right corner to discover the first of many secret passageways. Follow the unseen path east until you can go no further, then head north to emerge in a prison cell. Prise open the chest to find a mighty Power Bracers , then backtrack to the stairs.
Next, go north from the stairs and enter the prison cell to the west. Go towards the bottom-left corner and you’ll stumble upon another secret passageway. From here, you can navigate to the prison cell above and retrive a sturdy Genji Helm from the chest inside.
Next, continue all the way east from the prison cell above the stairs. At the end, head for the south-east corner where all the crates are. Here, hug the wall opposite the lantern to discover a predictable secret passageway along the south, which leads to the prison cell to the left.
Inside here is a chest containing a Safety Ring , which you’ll want to hang on to (or sell if you have enough). That’s three chests down and two more to go. From here, head north towards the north-east corner, where surprise, surprise, there’s a hidden path accessible via the bottom-right corner.
This will lead to the prison cell below, where you can recover a Genji Armor from the chest inside to complete your Genji collection (minus the gloves). Afterwards, head all the way west along the upper corridor. Before picking up the shield, enter the left-most prison cell.
Here, simply pass through the wall on the right, along the bottom, to reach the central prison cell and relieve the chest of its valuable Elixir . Finally, inspect the shiny object in the north-west corner to claim your prize: the Grant Marshal’s Shield .