Fairy Tail is joining up with other guilds - Blue Pegasus, Lamia Scale and Caitshelter - to defeat a dark guild named Oración Seis. These four guilds will each send out members to strike the six members of the Oración Seis down. From Fairy Tail, Natsu, Lucy, Gray and Erza are chosen. They are sent to Master Bob's villa (from Blue Pegasus) to meet up with other members of other guilds. They first meet the representatives of Blue Pegasus, the Trimens - Hibiki, Eve and Ren - and Ichiya. Afterwards, they meet Lyon and Shelly, whom they fought with before, and Jura from Lamia Scale. The episode ends with everyone surprised upon seeing Wendy from Caitshelter, a petite girl who arrives last.

Wendy is captured by the Oración Seis, and so is Happy! Erza is poisoned, and the poison is spreading through her body, which will eventually lead to her death. Erza requests for her arm to be cut off, but Charle says that Wendy can save her. Turns out, Wendy is the Sky Dragon Slayer, who has healing powers. The representatives intend to save Wendy and Happy, in order to be able to heal Erza. Oracion Seis intend to use Wendy's healing power to resurrect a certain person. Lucy stays behind with Hibiki to take care of Erza, while the others set off to rescue Happy and Wendy. On the way, Natsu, Gray and Charles are surrounded by Naked Mummy, who is working for the Oracion Seis, and have to defeat them. Wendy is ordered to revive a certain person, and that person is ... Jellal!

Acnologia arrives at the island and begins to destroy it. Seeing the Black Dragon of Apocalypse, Makarov tells his guild members to run while he fights it, but the fairies wouldn't leave without their master and decide to fight alongside him. However, their efforts ended up being futile as Acnologia releases his Dragon's Roar, seemingly destroying the island and everyone on it.

Natsu and his fellow Fairy Tail members come face to face with the eclipsed Celestial Spirit King... except the king is now more like a giant fiend without a face! Or more like he's got a giant vacuum cleaner tube for a face, which he uses to suck up his own planet, the captive Celestial Spirits, and if they're not careful, the Fairy Tail Wizards!

Erza manages to overcome Midnight's illusory magic, while Natsu, Gray, Lucy and Happy confront Brain's staff, Klodoa. Realizing Midnight's defeat, Klodoa explains that Brain has an alternate destructive personality called Zero that was kept sealed by the members of the Oración Seis using body link magic. The seal is released and Zero emerges and defeats Natsu, Grey, Lucy and Happy with ease. Erza, Jellal, Wendy and Charle make haste as Zero initiates Nirvana to fire upon Cait Shelter.

For their preliminary trials, Juvia and Lisanna face off against Erza, while Elfman and Evergreen find themselves standing against Mirajane. Meanwhile, Natsu enthusiastically battles against Gildarts, with a series of flashbacks detailing how Natsu had never once been able to defeat him since childhood. Just when Natsu believes he has gained the upper hand, Gildarts unleashes an immense aura of magical power, prompting Natsu to surrender in fear. Gildarts teaches Natsu the benefits that fear has in order for him to grow stronger, and tells him that he has passed his preliminary trial.

After being defeated by Gray and Loke, Mest convinces Wendy to help him look for a secret he claims to be hidden on the island. Worried about Wendy, Charle arrives on Tenrou Island together with Pantherlily, who doubts Mest's claims of being Mystogan's disciple and suspects that Mest may not be a member of Fairy Tail. Meanwhile, Levy and Gajeel pass through the only route devoid of opponents, Elfman and Evergreen defeat Mirajane, and Juvia and Lisanna lose against Erza. For the second part of the exam, the remaining participants are instructed by Makarov to search the island for the grave of Mavis, Fairy Tail's first master, within six hours. During their search, Elfman and Evergreen encounter the black-haired youth, who unwillingly unleashes a wave of lethal magic, though Natsu arrives in time to save his friends.

Mest is revealed to be a member of the Magic Council sent to Tenrou Island to search for incriminating evidence against Fairy Tail and disband it. He, Wendy, Charle, and Pantherlily are attacked and defeated by Azuma, one of Grimoire Heart's most powerful members, the Seven Kin of Purgatory, who easily destroys the fleet of council ships Mest had summoned for support. Makarov attempts to cast Fairy Law to repel Grimoire Heart, but the dark guild's master Hades counters the spell with Grimoire Law. Makarov recognizes Hades as Purehito, his predecessor as the master of Fairy Tail.

Natsu is overwhelmed by Zancrow's God Slayer magic, which proves superior to his own Dragon Slayer magic. Upon finding Makarov badly injured during his fight, Natsu regains his resolve and defeats Zancrow by nullifying his own magical power, allowing him to eat Zancrow's flames and combine their power with his own. Meanwhile, Lucy, Cana, Gray, and Loke fight Caprico, another member of the Seven Kin, while Mirajane and Lisanna fight Azuma.

Azuma learns of Mirajane's former identity as "the Demon" and straps Lisanna to a time bomb so he can fight Mirajane at full strength. Not wanting to lose Lisanna again, Mirajane sacrifices herself to defend Lisanna from the explosion. The remaining members of Fairy Tail learn from the Seven Kin their true goal: to resurrect Zeref and bring about the World of Great Magic, where only wizards would thrive while the rest of humanity would be subject to hell on earth. Meanwhile, Ultear finds Zeref and, after a brief battle, successfully captures him.

Gildarts fights Bluenote while Fried and Bickslow, who returned to Tenrou Island together with him, help Levy, Lisanna, and Pantherlily to fight Rustyrose. Meanwhile, Azuma reveals to Erza that he has used his magic, the Great Tree Arc, to absorb the magic-giving energy of the island's giant Tenrou Tree, destroying it and draining the strength of all the Fairy Tail members on the island except Erza.

Erza makes Azuma promise to return her guild's magical power if she defeats him. She herself is nearly defeated when Azuma uses the Tenrou Tree's magic, but receives her second wind upon hearing Jellal's voice and, drawing power from the tree's magic, cuts Azuma down

Natsu Dragneel, Lucy Heartfilia, Gray Fullbuster, Erza Scarlet and Wendy Marvell square off against Hades, where they are easily struck down. However, Laxus Dreyar storms in to save the day.

With a supercharge from Laxus, Natsu turns into an ultra-powerful Thunder-Flame Dragon! But will it be enough to rival the unfathomable strength of the deepest of magics? And will an exhausted Fried and Bickslow manage to finish off the tenacious duo of Yomazu and Kawazu?

There are only five days left 'til the Grand Magic Games begin, but Natsu and company still aren't ready for it. But then they meet up with Crime Sorciere, a small, independent guild led by an old frenemy. The members of this newish guild promise to help Fairy Tail "power up" in exchange for a favor...

In the first battle of the first day of the Magic Games, Lucy is pitted against Raven Tail's Flare, whose long locks are deadly.

The battles continue as wizards from the competing guilds go spell-for-spell in the stadium center. When Jellal-as-Mystogan takes on a member of Lamia Scale, will he be able to make up for all of Fairy Tail's previous losses?

After being completely annihilated on the first day of the Grand Magic Games, Fairy Tail tries to recover and keep high spirits for the remaining rounds. Elsewhere, the captain of the guard is up to something suspicious, and Carla has a terrible vision.

The battle portions of the second day continue with Kurohebi defeating Toby Horhorta and then showing his crueller side by ripping Toby's prized sock. Whilst everyone is watching the Games, malicious activities seem to be happening in the background, with Wendy, Porlyusica and Carla almost being kidnapped! In the midst of this chaos, an error by Arcadios sees Elfman fighting Bacchus.

The last battle of the second day pits Kagura, Mermaid Heel's strongest wizard against Yukino, a young Celestial Spirit Wizard on Sabertooth's side.

In the event called Pandemonium, Erza has opted to take on 100 powerful magic-generated monsters by herself...

The third day of the Grand Magic Games proceeds into the battle portions. The first match, Mermaid Heel's Millianna and Quatro Puppy's Semmes, results in an unexpected win. Rufus Lohr easily dominates Eve Tearm in the following match. Then, in the next match between the father-and-son Guilds, an unexpected play from Raven Tail seemingly gives them an incredible advantage against even Laxus Dreyar.

Laxus takes on Raven Tail's elite, but they're after something more than a win! And then there's Wendy vs.

As Fairy Tail happily parties in a bar to celebrate their earlier victories, others all around Crocus contemplate the harsh realities of things they have witnessed on the third day, and those to come. Malice also lurks in Sabertooth, as, in the Naval Battle event the following day, Minerva succeeds in brutally attacking Lucy as a demonstration of her guilds power.

The fourth day of the X791 Grand Magic Games continue with the second match of the day, Lamia Scale against Mermaid Heel. Both sides struggle to win, only to end the battle in a draw, leading to the beginning of the last match between Fairy Tail's and Sabertooth's Dragon Slayers.