Lightning's Story: Requiem of the Goddess (ライトニング編『女神の鎮魂歌』, Raitoningu Hen "Megami no Chinkon"?, lit. Lightning Story "Requiem of the Goddess") is a downloadable extra scenario of Final Fantasy XIII-2. It can be considered as the game's true ending.
It was released worldwide on May 15th, 2012, for both PlayStation Network and Xbox Live Marketplace. It also is included in the Japanese re-release version of the game, Final Fantasy XIII-2: Digital Contents Selection and the Microsoft Windows port.
The scenario starts with the main menu screen where the player can see Lightning's status. Lightning can level up to 10 and has six paradigm roles: Paladin, Knight, Mage, Conjurer, Sorcerer, and Shaman. Paladin is a Commando-based role, Knight is a Sentinel-based role, Mage is a Ravager-based role with focus on lightning-attribute magic, Conjurer is a Synergist-based role, Sorcerer is a Saboteur-based role, and Shaman is a Ravager-based role with focus on wind-attribute abilities. Lightning's level can be adjusted and earning 5-star rating from the second boss when Lightning is Level 9 or lower, will result in Lightning's Knight of Etro version joining as a Paradigm Pack ally.
Locking the Valhalla -??? AF- gate in the Historia Crux will reset "Requiem of the Goddess;" this allows the player to obtain Lightning's monster crystal again if she has been infused into another monster.
The eternal battle between Lightning and Caius rages on until Caius abruptly disappears and Lightning sees a vision of Serah's death by her Eyes of Etro. Caius strikes Lightning down as she is caught off guard, but before he can deliver the final blow, she is taken away by chaos.
She comes to in the remains of Etro's temple where she finds Serah's soul, restrained and surrounded by chaos, manipulated by the spirits of Yeul who claim Serah will remain with them until the end of time, melting into darkness once the world ends. They manifest Caius whom Lightning battles, after which Caius transforms into Chaos Bahamut and flies towards the beach where Lightning continues to fight him.
After dispatching her opponent, Lightning mounts her Eidolon Odin and encounters Shadow Yeul, demanding her to let Serah go, only for her and her Eidolon to be swallowed by chaos. As she floats through the Historia Crux, Lightning contemplates that carrying out the goddess Etro's will would atone for her past sins, and concludes there is nothing left for her, not even hope. She is made to realize her actions led to her sister's death as Lightning sent her off on her journey with Noel.
Back in Etro's temple, mourning over her sister's body, Lightning sees Serah's spirit on the throne. Serah reveals she knew of her eventual death yet continued on her journey so they can be reunited and has no regrets. As Serah's spirit fades away, Lightning runs toward her and finds herself in a white void in Serah's embrace. Serah tells Lightning to not give up hope and always remember her, even if she vanishes from the world, promising they will meet again.
Returning to the temple, stairs leading up to Etro's throne manifest and Lightning climbs them with newfound resolve. To ensure Serah's memory lives on and to preserve the world's existence in Etro's place as her true atonement, Lightning sits on the goddess's throne and enters crystal stasis, waiting for the day she will awaken at the end of eternity.