It's a coffer of souls. If I collect enough soul fragments, Dajh'll wake up... least that's what I was told.
The coffer of souls is an object in Lightning Returns: Final Fantasy XIII. When the soul fragments of a certain person are collected in it, the person will wake up from their soulless dream, provided the environment around them pleases them. Its origins are unknown.
Some time before Lightning's visit to Sazh Katzroy in the Wildlands, Lumina presented the coffer of souls to him as he tried to find a way to wake his son, Dajh, from his soulless sleep. Despite his escapades across Nova Chrysalia, he was unable to find a single soul fragment.
When Lightning visits Sazh, she notices Dajh's condition and Sazh explains her the situation. Sazh leaves, continuing his search. At Sazh's doorway a black chocobo chick points Lightning to the fragment of mischief, one of Dajh's soul fragments. As Lightning continues her search she obtains the fragment of smile from Chocolina, the fragment of radiance from a soul seed hunter, the fragment of courage after defeating a Zaltys in a special Slaughterhouse challenge, and the fragment of kindness from the Cactair in the Dead Dunes. During the hunt for the soul fragments, Lumina frequents Lightning saying she feels sorry for Sazh though Lightning doubts her words.
After Lightning collects all the soul fragments she returns to Sazh's home. She places them in the coffer of souls, but no response comes. Lumina reveals Sazh is the reason Dajh is not waking up because the boy doesn't want to see his father frustrated. Sazh's chocobo chick aggressively pecks Sazh and initiates a race between herself and a model airship. During the race Sazh brightens up and the coffer of souls reacts releasing Dajh's now united soul, waking him up.
soul, in many religious, philosophical, psychological, and mythological traditions, is the incorporeal and, in many conceptions, immortal essence of a person, living thing, or object.The