It is highly probable that on your journey through Final Fantasy X-2, you’ll discover ‘Crimson Spheres’. Upon collecting all 10 of these spheres, you will be able to enter the Den of Woe, which is located in the Mushroom Rock Road.

Below we detail the chapter you’ll need to find the Sphere on, aswell as the method used to get it.

How to get the Spheres:
Sphere 1 (Chapter 3): The room with Vagnagun in it.
Sphere 2 (Chapter 3): You’ll gain this sphere when you defeat the aeon, Ixion.
Sphere 3 (Chapter 3): You’ll gain this sphere when you defeat the aeon, Ixion.
Sphere 4 (Chapter 3): Leblanc’s room.
Sphere 5 (Chapter 4): After the “1000 Words” concert, you’ll gain the sphere from Leblanc.
Sphere 6 (Chapter 5): Cloister 0 in Bevelle.
Sphere 7 (Chapter 2): Visit Den of Woe after the chocobo event.
Sphere 8 (Chapter 5): Complete Cloister 20 in Bevelle.
Sphere 9 (Chapter 1): After the Foggy Fiend Frenzy, pay a visit to the Den of Woe.
Sphere 10 (Chapter 2): Found in Ormi’s room during the “Infiltrate Syndicate” mission.