The Oracle Room

The Cave of the Seven Stars is an end-game dungeon where you can find the best weapons in the game, as well as face the strongest enemies available. To access it, you have to reach the last savepoint in Revorse Tower, right before facing the final boss in the main story.

From the last savepoint in Revorse Tower, head south past the teleporter you used to get on this floor. South of it is another teleporter leading to B1F. Continue to the right until you reach a large room with four doors. Take the south, use the teleporter and you’ll be in the Oracle Room.

You can find the game developers’ NPCs inside the rooms here. You can talk to them if you want. There is also a merchant here with the complete inventory so resupply first before moving forward. The stairs going south leads to the Labyrinth of Champions in Ancient Roak so you can ignore that. Unfortunately, this dungeon isn't connected to Roak.

If any of your characters has Oracle level is 10, head to the rightmost room to find a chest with Magical Jar. This fantastic accessory is like the Mischief or Trickster accessories from Star Ocean: Second Story which allows your party to acquire items by simply carrying it around. Equip it to your reserve party member, preferably to someone with high LUC to receive better items more frequently. To enter the actual dungeon, take the leftmost door.