You will encounter this Cie’th Stone while travelling through the Sulyya Springs in the Ceiling of Sky when you first arrive from the Mah’habara Subterra. If you are in Chapter 11 though you will only be able to complete it if you opted to complete the optional missions back in the Archylte Steppe and the last Mission in the Mah’habara Subterra.
This Cie’th Stone is located in the Ceiling of Sky area at the entrance to the Sulyya Springs. You can grab it as soon as you depart from riding Atomos out of the Mah’habara Subterra area.
The mark(s) for this Mission are further inside the Sulyya Springs in an area called the Subterranean Lake which is the vast open area just up ahead from where the Cie’th Stone is located.
Walk over towards the left side of the screen and examine the pool of water from the top of the cliff to trigger a short cutscene involving a fal’Cie. A few new platforms will emerge out of the water.
Travel towards the cliffs on the opposite side of the whirlpools and use the illuminated blue circles to climb your way up to the top. The group of four Uridimmu can be found protecting a Treasure Sphere in this area.
Class: C
HP: 45,900
This mark is the same as the one you fought for Mission 02 - Goodwill Hunting except this time there are more of them.
The four Uridimmu enemies are very easy to defeat. They can each use an attack called “Virulent Breath” which can potentially inflict 
Poison on your party members and may need to be cleared if you’re having difficulty withstanding the damage. Just swap to a paradigm with a 
Medic and give them some time to cast 
Esuna.
Cobaltite
Bomb Shell (x5)Using the navigation links below, you can also quickly jump back to the Chapter 11 strategy guide, straight to the next mission, or back to the main Mission index menu:
