The Hollow (虚無, Kyomu, lit. Nihility) is the main antagonist force of Final Fantasy Brave Exvius Season Three. A mysterious, unknown entity that appears in multiple worlds with the intention to deprive them of both living and immaterial things. The Hollow and its proxies are protected by the Hollow Keepers.
Not much is known about The Hollow, other than that it appears in the worlds connected to the Farplane and actively ravages them to strip them of both living beings or even objects, for no apparent reason. An organization known as the Hollow Keepers, defend the Hollow and allow it to cause havoc largely for personal reasons, but mostly believing that worlds are better off without whatever the Hollow absorbs.
The Hollow and the Hollow Keepers are opposed by a group dubbed by the latter as Hollow Breakers, individuals from different worlds tasked with boarding the Farplane Express to travel the worlds connected with the Farplane to restore what the worlds lost.
In a certain day, when Fina who is living in Grandshelt is cooking for Physalis who managed to join the Knights of Grandshelt, wonders about her future, she ponders about her weakening powers which he believes is a result of her missing counterpart. Suddenly a shining Crystal appears before Fina and a voice pleads Fina for help. Following Rain and Lasswell's example, Fina decides to help the voice, touching the Crystal on its instruction and transforming into a Blue Mage. Fina is soon transported to the Farplane where an station appears before her along with the Farplane Express. Its conductor, Rinora appears to take her with him as her name appears on the list of passengers. As Fina boards the train, Rinora explains that its passengers are meant to restore that which the worlds lost.
Fina is joined by fellow passenger Bruce and the two travel to Wohlstok. As Fina and Bruce make their acquaintances, Bruce reveals he has casted away his past, whereas Fina has no memory of her own past. As the two travel to Silent Village Corte they find its citizens under the attack of monsters, but the citizens do not react to the monsters, forcing Fina and Bruce to defend them. Fina wonders what is wrong with the people and Bruce explains that it is the work of the Hollow that has taken people's emotions away, thus depriving them of fear. He continues that the Hollow manifests itself through a wormhole and if it is closed, the Hollow will be repelled, successfully restoring the world to normalcy.
Fina and Bruce hear a scream and rush to encounter a young woman known as Daisy who has retained her emotions and fights to protect a pair of children attacked by monsters, but who refuse to escape due to their inability to feel. Fina and Bruce help Daisy repel the monsters.