The Hollow Keepers is an organization in Final Fantasy Brave Exvius tasked with protecting The Hollow. The Hollow Keepers are the main antagonists of Season Three, succeeding the Sworn Six of Paladia and The Orders.
Not much is known about the Keepers, other than that it is their duty to protect the Hollow and allow it to ravage the worlds linked with the Farplane. The Hollow Keepers have shown personal motivations to defend the Hollow and its rampage, as they largely believe the worlds are better off without whatever the Hollow absorbs.
They are opposed by the Hollow Breakers, a group that travels the Farplane Express who are destined to fight the Hollow's influence.
Fina and Bruce run into the Hollow Keepers in Wohlstok, a world in the Farplane. They find a town whose people have lost emotions, and by proxy, fear, as they are attacked by monsters but don't try to protect their lives.
Saving the villagers from the monsters, Fina and Bruce find Daisy, a local stage actress who—unlike the rest of the world—retains her emotions. They briefly encounter Mazurka, a Hollow Keeper who chastises them on their attempt to restore the people's emotions, claiming they are not suffering. The party watches Daisy perform in an attempt to rekindle people's emotions, but she fails.
The party follows a Silvery Fog that indicates a nearby wormhole from where the Hollow appears. They encounter a Hollow Dragon protected by Mazurka who insists on the party's foolishness in trying to restore emotions. The party defeats her and Mazurka retreats. The party defeats the Hollow monster and seals the wormhole as it spawns Roca, a mysterious baby girl whom they take with them. The world's emotions are not yet restored, as they learn there is another wormhole to seal.
When the party returns to the town they meet Milieta, an actress and rival to Daisy, who has lost her emotions. Daisy tries to make her remember their acting time together, but to no avail. Mazurka tries to convince the party to desist in their quest to return people's emotions, as she narrates her tragic story of bullying (without referring to herself) as proof that there are people who have been saved by the lack of emotion.
The party is initially awestruck at the idea, but nonetheless Fina reaffirms her belief that emotions are necessary. Daisy has Milieta and herself perform "Of Sword and Shield" on stage, where the latter recovers her emotions through her passion for acting, causing Mazurka to grow alarmed.
With Milieta's help the party finds the next wormhole, but are barred by Mazurka. After Fina duels and defeats her Mazurka lies terrified at the prospect of being bullied again. Fina offers her a hand of friendship, leaving Mazurka confused. Calmed down, Mazurka retreats and wishes for Fina to not die. The party defeats the second Hollow monster and seals the wormhole, restoring the world to normalcy. Daisy joins Fina and Bruce in their quest.
Mazurka lies in an unknown place, wondering the value of friends. Multiple Hollow Keepers appear and reaffirm their alliance to protect the Hollow, which they believe creates a true ideal world devoid of lies. Mazurka tells her comrades about Fina's party.
Fina and her friends arrive at the Kingdom of Illumia where they are attacked by the Royal Guard on sight by orders of the Queen. They are saved by Melo, a magic user with a lazy demeanor, who claims to know where a Silvery Fog can be found. They encounter Kalmia, a mysterious woman who attacks them, but is defeated. Kalmia claims that she has been strengthened as a result of what has been lost and departs, leaving the party to believe she is a Hollow Keeper.
Fina's party runs into the Royal Guard again and a battle ensues, unmasking them as an all-woman unit, making the party realize that the Hollow has taken the world's men away with the exception of Melo for unknown reasons. Melo guides them to the cave where he witnessed the Silvery Fog, but they only find a worm monster. The party defeats the monster, but don't find a trace of the Hollow. They are ambushed by the Royal Guard and immobilized by paralyzing arrows as the soldiers seize Melo away on orders of the Queen. Kalmia appears and heals the party, asking them to not interfere.
The party returns to the kingdom to save Melo, who is sentenced to death. The party tries to interfere, thinking the kingdom to be run by Hollow Keepers hellbent on ridding the world of men. Kalmia explains it was not the Hollow who took the world's men, but an illness, and that it was not men that was lost from the world, but magic, exposing Melo as a rampant magic-using criminal who has repeatedly interfered with the kingdom's attempt at recovering magic. Melo confirms and reveals himself as the true Hollow Keeper, freeing himself from his ropes and casting a spell on the Queen, turning her into a bronze statue as he retreats.
Kalmia unsuccessfully tries to heal the Queen and realizes they must have Melo remove the spell. On their way to pursue him, Kalmia explains that she is a doctor and that their world has an illness known as the Withering that targets men that can only be treated with magic. The Queen had used a special stone to teleport the world's men, the King included, to a safer world while the women were left to recover magic, but all their ventures have been thwarted by Melo.
When the party finds Melo he reveals he desires to rid the world of magic because it can lead to—in his words—"poor choices". The party pleads that without magic people will die, but Melo refutes it as a natural occurrence. Not expecting to be understood, Melo fights the party who try to not kill him so he can remove her spell on the Queen. Melo reveals himself a magical prodigy and unleashes a powerful magic blast, severely injuring the party. Seeing that Roca was unaffected by his attack, he takes an interest in the mysterious baby and kidnaps her, intending to turn her into a Hollow Keeper.