The story in the first season of Final Fantasy Brave Exvius focuses on the world of Lapis and Rain and Lasswell, two young knights who meet a mysterious girl called Fina and end up fighting the mysterious and powerful Sworn Six of Paladia to protect the world's crystals.
Rain and Lasswell are aboard their airship, battling a horde of monsters. Perplexed by the monsters' strange behavior, a young woman trapped in a crystal appears before them and begs assistance. She leads them to the Earth Shrine, where the Earth Crystal is under attack by Veritas of the Dark. He proves to be a formidable foe, destroying the crystal despite their opposition. As the two knights lie defeated, the girl reappears, grants the power of visions so that they may save the world, and teleports them outside the crumbling shrine. As Rain and Lasswell find their men killed and airship destroyed by Veritas, they decide to journey on foot to Royal Capital Grandshelt and report the events to the King of Grandshelt.
On their way to the castle, they find it under siege, burning down by mysterious figures known as the Sworn Six of Paladia lead by Veritas of the Dark, who tries to kill the knights. Rain is saved by Fina, the mysterious girl that was trapped in the Crystal and who has no memories of herself. The trio travel the world intending to put a stop to the Veritas' rampage. Traveling to Lanzelt Ruins, they come across Veritas of the Dark who was retrieve powerful artifact known as the Sacred Ring of Paladia. The trio come close to defeat him, but the Darklord manages to overpower them and take his leave.
The trio then travels towards Dirnado where they meet the young engineer Lid who is hopeful to inherit the title of Cid as the best engineer. On their way they find Veritas of the Heavens who has been kidnapping Dwarves for an unknown purpose. Joined by Lid, the party comes across Evan, Lid's older brother who is on the servitude of the Heavenlord and repairing an ancient, powerful airship known as the Invincible. Trying to protect the Wind Crystal, the party faces the Heavenlord, unmasking him as Cid, the legendary airship engineer for whom future engineers are titled after on his honor. Cid destroys the Wind Crystal, unleashing The Heart of Babel a device needed to power their airship for their machinations.
The group makes their next stop at the Olderion Federation where they encounter the strategist Nichol and their brother Elle, who are in search for their sister, the Water Priestess Luka who can purify the waters to deter the increase of monster activity. After finding Luka, the party comes across Veritas of the Waters a sadistic mage who has wounded the Leviathan polluting the waters of the nation. Through Luka's help, Leviathan comes back to its senses and forces the Waterlord to retreat, however, she would attempt to flood Olderion and kill its populace. Fina fights her and regains her memories, adopting the persona of Dark Fina. With the help of pirate captain, Mercedes the party is able to go to the Water Shrine to protect the Water Crystal from the Waterlord, but Rain awakens a mysterious power that is too much for him to handle and threatens his life. Elle dies in combat but his death prevents the trap the Waterlord had planned, allowing the party to defeat her. Dark Fina uses the remaining power of the Water Crystal to restore Olderion to normal and saving Rain, but Luka must pray underwater to purify the waters. Nichol decides to join the party.
The group heads to the militarized nation of Zoldaad who is in the midst of a civil war with a rebel faction. The party is coerced to join by the rebel leader Jake in order to save Grandshelt from an invasion. With Jake's help they sabotage key facilities. The party faces Veritas of the Flame who easily defeats the party and is reveals he crafted Lasswell's blade that has hidden potential. On their way to chase the Flamelord, Lasswell sustains grievous injuries he keeps hidden. The party battles the Flamelord and are able to win through Lasswell's determination to win that unlocks his blade's power, but collapses from his injuries. The Darklord restores all fighters to their top condition and a new battle ensues, with the party's victory. Jake, however, destroys the Fire Crystal in order to save his nation, releasing Bahamut the strongest Esper from its slumber. The party soon comes to a direct confrontation against Zoldaad dictator, Sozhe who is in truth, controlled by Dr. Lazarov, a mad scientist obsessed with immortality. After freeing crown prince Shera, the party is forced to kill Sozhe and soon pursue Dr. Lazarov who attempts to genocide the nation from atop the Invincible but is blasted by Bahamut's Megaflare. The group battles Dr. Lazarov and defeat him, freeing Zoldaad from its reign of terror.
As Jake joins the party they meet Sakura, a deceptively young-looking old mage related to the Veritas who promises to aid the party and on her request, march towards Mysidia the land of mages. The group comes to face Veritas of the Light and Veritas of the Earth Sakura's older sister and Fina's rival respectively. The Earthlord restores Fina to her older self but at the risk of endangering the other Fina. The party is forced to travel to a memory world in order to rescue Fina, and learning of the Veritas' past in the process as warriors from the nation of Aldore in the world of Paladia who battled the forces of Hess in a bloody global war, and were betrayed by their homeland and sent to Lapis through the power of the Eight Crystals, and their plot to destroy them to return to their world to enact revenge on their former masters, despite the catastrophic consequences for both worlds. The party succeeds in saving Fina, splitting her in her two selves. The party defeats the Lightlord and Earthlord, and now closer to the truth than ever, and learning of Rain's father's involvement in the entire affair. Sakura joins the party.
Their next destination is Gronoa, a continent plagued with toxic miasma and residence of the last, Dark Crystal. Helped by aides of Shera the party survive the deadly miasma. The party come across the Lightlord once more who chastises Sakura for betraying her. As the party defeats her, the Lightlord taunts Rain to kill her revealing she killed her mother, Sophia, but Rain refuses. The party then finds the Dark Elf, a former enemy of the Veritas who turned mad after 700 years of imprisonment. The party tries to stop him but his suicidal devotion to destruction allow him to overpower them. The Lightlord, blasts the former Sage of Hess and destroys him. As both parties prepare for a final battle, Veritas of the Frost a lost member of the Veritas takes a village hostage and forces them to fight in a tournament to determine the strongest and satisfy his bloodlust. Lasswell obtains a massive power boost through disciplined training and easily overpowers his comrades, including Rain and begins to feel guilty over thoroughly beating his adoptive brother, contrary to his inferiority complex. Rain, however awakens his true power and duels Lasswell once more, defeating him with the two coming to terms with one another. The Frostlord then fights the party for the Dark Crystal and is beaten, but soon after the Veritas appear to destroy the last Crystal. The Frostlord is revealed to be none other than Raegen, Rain's father and the true leader of the Sworn Six, leaving the latter to question the Darklord's identity.
A major battle ensues between both parties but as the land begins to collapse they are teleported to the land of Pharm. Nichol boiling with a drive for revenge against the Waterlord's crimes relentlessly pursues his hated enemy, with the party behind him as they terminate the Veritas one by one. Soon Nichol comes across his nemesis who is revealed to be Folka, the first Water Priestess of Olderion and his long ancestor, who uses hypnosis techniques to create a bloodthirsty personality to fight as a warrior. Nichol is unable to claim revenge and ultimately forces her to devote herself to help others as punishment, to which she agrees with. The party eventually find a weakened Lightlord along the Darklord, the only member left capable of fighting. A decisive battle ensues with the party's win exposing the Darklord as a vision of Raegen created by the Lightlord. Their victory, however, is short lived as Sol a former lieutenant of Hess turned a nihilist psychopath by his imprisonment, destroys the Crystal with the intention to annihilate both worlds of Paladia and Lapis, the Darklord dies at the hand of Behemoth K, Sol's companion.
The party goes after Sol to stop him climbing the Land of the Crystals, with little time left as all Crystals have been destroyed. As Fina begins to disappear due to two of her being unable to exist at the same time, Dark Fina with the help of a reformed Lightlord and Waterlord, performs the ultimate sacrifice, turning herself into a new Earth Crystal, allowing Fina to live and granting her the powers of a Sage of Hess allowing the party to advance. They come to face Behemoth K who proves too powerful, so the two Veritas teleport themselves away with him, enabling the party to pass. The party catches up with Sol as he plots to open the Interdimensional Gate that will allow both worlds to collide. Sol is defeated but reveals his trump card, the Chaotic Darkness a monstrous vision made up of humanity's evil with whom he tries to destroy the world.
The powerful Vision creates a bizarre distortion known as the Wandering Lands which the party navigates. The party comes to face Behemoth K who has killed the Veritas and teleported chasing them. Furious over the death of their reformed comrades, the party defeats the weakened beast, who released from his insanity begs the party to kill Sol to save him from himself. The party comes face to face with Sol and his diabolical vision, and manage to defeat both of them after a lengthy battle, Sol retreats vowing to kill Rain, disgusted at his sense of justice. Unfortunately, the Chaotic Darkness mutates into a more monstrous form, before trying to lay waste to Lapis. With the party intending to defeat the horrendous beast, the prayers and hopes of all inhabitants of Lapis irradiate powerful light that weakens the monster, allowing the party to terminate the mutant vision. Before they can celebrate, Rain and Raegen awaken to their hidden power in an attempt to force close the gate and prevent a catastrophe. Sol, however, regaining his strength tries to ram himself against the Gate to force it wide open. Rain clashes with him and the two disappear as Rain's Crimson Saber falls with the party in disbelief. Lasswell is confident Rain is alive and vows to find him.