Achilles Core Fragment A
Location: Depths: Fiery Oblivion
From the Fiery Oblivion mistle, follow the path north and take a right after the large rock. Defeat the group of enemies here then keep heading straight until you reach a ledge leading into a cave. Drop into the cave to find the vestige in the white grass. As you approach the vestige, you will be ambushed by a whole bunch of enemies!
Achilles Core Fragment B
Location: Depths – Fiery Oblivion
From Achilles Core Fragment C, jump off the small cliff and follow the path through a tunnel on the right. Follow the ramp on the other side of the tunnel up to reach the top of the tunnel. The fragment will be here in a patch of white grass.
Achilles Core Fragment C
Location: Depths – Fiery Oblivion
Follow the path west from the Fiery Oblivion mistle until you come to a rock archway. Pass through the archway and take the right path to locate the fragment at the end of the path.