Mwynn (ムイン, Muin?) is a character in the Fabula Nova Crystallis: Final Fantasy mythology. She does not appear in person, but is part of the background lore. Not mentioned by name in Final Fantasy XIII, she is briefly alluded in Final Fantasy XIII-2, where a fragment discovered in the Void Beyond is named "Mwynn's Tenderness". An accessory called the "Amulet of Mwynn" also appears in Final Fantasy Type-0.
The Fabula Nova Crystallis mythology was revealed in a video shown at Square Enix 1st Production Department Premiere event on January 18th, 2011. The universe of the Fabula Nova Crystallis series is divided in two – the mortal world, the realm of the living, and the unseen realm, the realm of the dead. Mwynn is the god Bhunivelze's mother, and was killed by her son who wanted to take full control of the mortal world. As a result, Mwynn was sent into the unseen world.
Despite achieving his goal of total control of the mortal world, Bhunivelze became troubled. He believed that Mwynn had placed a curse on the realm of the living so that it would one day be destroyed. To put a stop to the curse, Bhunivelze sought to destroy his mother once and for all, but was unable to reach the unseen world without giving up control of the mortal world. To find the entrance to the realm of the dead, Bhunivelze created the god Pulse, tasked with searching the world for the door to the unseen realm.
To assist Pulse, Bhunivelze created the goddess Etro, but became distraught to discover that he had unknowingly created her in the likeness of Mwynn and as a result, Bhunivelze gave Etro no powers. To replace Etro, Bhunivelze created Lindzei, tasked with protecting the world and Bhunivelze himself. With the deities at work, Bhunivelze put himself into a deep crystal sleep, to be awoken only when the door to the unseen world was found.
Etro became distressed over her lack of power and purpose in the world. Out of despair, Etro killed herself and entered the unseen world where she discovered Mwynn being consumed by an energy mass known as chaos. With her last breath, Mwynn tasked Etro with protecting the balance of the universe, for if the balance between the visible and unseen realms was to be disrupted, the universe itself would collapse. Mwynn told Etro she must protect the world balance, before being fully consumed by chaos.
Mwynn is mentioned indirectly by Bhunivelze in the Japanese release as the one who sought to destroy the world whom he fought and defeated. She is also mentioned by name by Bhunivelze+ when he refers to humanity as her "children".
Mwyn is Welsh for "gentle" and "kind".