You can find the Ra’s Mirror below the prison room of the Cathedral of Blight. This unique item can’t be found or bought anywhere else, and even if you don’t need it to do anything in the story, it’s very useful against some specific enemies.

Reaching the Cathedral of Blight 

Recommended level: 36

After finding the Fire, Air and Earth Amulets, head back to the Sea Dragon. The Water Spirit will show up, giving you the Water Amulet. With all four amulets you can now head to the final dungeon in the story.

Land anywhere and get up on the Skystone. Head for the Cathedral of Blight, on the small island in the middle of the world. The main entrance is locked, so enter the cathedral through the roof.

Finding the Ra’s Mirror

The layout of the tower is the same as how it was before. The only difference now is that it’s infested by monsters. 

Fall into the hole on the roof and walk straight south to get down one floor. Get to the opposite side of the room and go down the stairs again.

From here go down another floor, get to the base level and enter the northeastern room. Go up the stairs and take the exit to the north.

Walk to the other side of the balcony and take the stairs down on the east side of the room. Go down again and you’ll be in the prison room. Fall into the giant pit in the middle.

From here, just take the central stairs and get to the northern side of the room to find a chest. Open it to get the Ra’s Mirror.

Congratulations! The Ra’s Mirror is yours. This item can be used in battle to nullify Morph, a spell used by some enemies, like the Admirer and the Knight Shift, to turn into a clone of your party members. The clones get more powerful the more you level up your party, but their base form is always really weak.

You can cast Evac now or you can keep exploring the Cathedral to try and find the four pieces of the Saint’s equipment.