The Cathedral of Oblivion is a set of bonus challenge dungeons that appear in Star Ocean: Integrity and Faithlessness.
The entrance pathway of the Cathedral of Oblivion
While exploring the world, the player will occasionally find portals that lead the party into the Cathedral of Oblivion. The Cathedral is host to a series of battles; the number and difficulty of which is increased after the player clears Chapter 6 (defeating Der-Suul) and again after clearing Chapter 10 (defeating the Illustrious Manticore). When entering for the first time, the player is presented with a message warning them of the impending danger, after which they are free to turn back, or take on the challenge.
The challenge consists of 3, 5, or 7 rooms of enemies depending on the player's story progress. The final room will contain a powerful boss, along with a chest reward. When the Cathedral expands due to story progress, the boss in the room that was previously the final one will disappear and be replaced with normal enemies (meaning the player must only ever fight one boss to escape). All chests will remain in their original rooms, preventing the player from missing any of the rewards - so long as they can complete the now more difficult challenge.
The 3rd iteration of the Cathedral offers each party member's strongest weapon (excluding those found in the Maze of Tribulations) as its ultimate reward. If the player intends to enter the Maze, defeating the Cathedrals first is a wise choice.
The entrance portals appear in several areas, but are not guaranteed. Thankfully, simply leaving and re-entering the area will grant the portal another chance to appear. Moreover, the portals have an icon that is visible on the map when they appear (which can be expanded by pressing the Options button), making them very easy to locate.
While aesthetically identical, each of these locations have different rewards with varying enemy strength (listed here in increasing difficulty):
- Coast of Minoz (Blue Talisman, Blood Chain Mail, Asclepius)
- Resulian Plains (Green Talisman, Duel Armor, Arcadian Serenity)
- West of the Eastern Eiheid Mountains (Red Talisman, Atrementous Usurper, Carbuncle's Prison)
- Trei'kur (Faerie Band, Bloody Knuckles)
- Northern Territory of Sohma (Healing Band, Chrome Nightmare)
- Alcazar of the Golden Age A2 (Farwell)