Gray Fullbuster vs. Doriate

Gray Fullbuster vs. Doriate is a fight fought between Mage of Fairy Tail, Gray Fullbuster and Dark Mage of Succubus Eye, Doriate.

Prologue
Shortly after arriving in the Sun Village, the Fairy Tail Mages sent on the mission by Walrod Cken encounter a group of Treasure Hunters from the Sylph Labyrinth Guild who seek the Eternal Flame, a treasure of the currently-frozen village. Seeing that they have a vial of liquidized Moon Drip with which they intend to steal the flame, the Fairy Tail Mages give chase, seeking to take the vial for themselves. After running away for a while, the Treasure Hunters eventually grow tired of it and stand their ground, beginning a battle. The battle does not initially go the way the Fairy Tail Mages had intended, as the Treasure Hunters prove to be worthy adversaries who are able to counter their moves and deliver a capable challenge, even for the Grand Magic Games winners.

The Treasure Hunters reveal that they're no ordinary Treasure Hunters as they were the winners of the Daihihou Enbu, a competition similar to the Grand Magic Games for Treasure Hunter Guilds. However, as they are revealing this, Gray uses his Magic to subtly steal the vial of Moon Drip from them. The two groups compete with one another over the bottle, with the Fairy Tail Mages tossing it to one another to keep it away from the Treasure Hunters. As Carla throws it to Happy, he is unable to catch it and thus allows it to break against the ground, much to everyone's shock. However, it is revealed via this spill that such a small amount would not have saved the village and from the small amount of ice melted, Natsu hears a strange voice and runs off to determine what it is, with his teammates and the Treasure Hunters following him.

During the chase, Gray separates from the rest of the group. Winding up on top of a small cliff, Gray spots a mysterious man and asks if he is a friend of the thieves. The Mage named Doriate expresses irritation with his finding of multiple Fairy Tail Mages one by one. Seeing his mouth's appearance, Gray questions him on it and is told that he will be eaten. As the man jumps up to the cliff, Gray suddenly finds himself in the body of a child. Suddenly distraught by memories of his childhood, as well as the resemblance of his current opponent to that of Deliora, Gray screams in terror just as the demonic man arrives. The man tells Gray that those turned into kids by his Magic may remember their childhood occurrences but he doesn't care. Held by the neck, Gray is told that he is on one side of the gate to the underworld and must never go across it, but does not listen. Suddenly, he hears a voice which tells him that Deliora is gone. Though he tries to rationalize his fears, the voice tells him to be strong for his friends. Recognizing that the voice as Ultear's, Gray freezes the man's hands, freeing himself. Thinking about how parts of his past all seem to be in the present, Gray asks the man if he was the one who froze the village. As the man says that he is, Gray criticizes his use of Ice Magic and states he will show him what real Ice Magic can do.

Battle
Hearing Gray's proclamation, Doriate is perplexed and tells the child-bodied Mage that the Law of Retrogression Magic does not give back one's youth, but rather, it decreases their power, speed, stamina and Magic. As he is about to tell Gray to simply give up, Doriate takes a step back and finds himself standing on an ice-made extension of the cliff created by Gray back when Doriate took a step backwards. Destroying the extension, Gray causes Doriate to fall off the cliff and land on his bottom. Asked when he did so, Gray states that not all of his abilities have been lowered and his imagination has actually been increased, thus allowing him to use his Ice-Make Magic to its fullest extent.

As Doriate climbs back up the cliff and looks around, he does not see Gray anywhere and calls out to him. From beneath, Gray calls out to him, revealing that he created a layer of transparent ice. Dissolving the ice, Doriate falls on a frozen bush, injuring him while Gray creates and Ice-Make: Hammer. However, its diminutive size forces Gray to turn it into a pile of snow, bringing Doriate chills. Noticing this, Gray tells Doriate that he now knows he didn't freeze the village as he said he did, as someone using Ice Magic would not feel the cold the way he does. Realizing through this that Doriate simply turns his opponents into children so he has an easy time beating them, Gray criticizes his strength.

With that, Gray suddenly finds his body returned to normal, much to his surprise. Suddenly, a snarling Doriate makes a jump for Gray, which he closely dodges. Taunting him about the cancellation of his Magic, Gray is suddenly punched to the ground. Taking a look at Doriate once again, Gray notices a significant change in his appearance, questioning for a moment whether it is a spell similar to Mirajane's Satan Soul before realizing that it is different. Remembering Deliora, Gray realizes that Doriate has turned into a demon from the Book of Zeref. Shocked by his transformation, Gray is unable to retaliate as he is knocked into the ground by Doriate. Sending sound waves into the sky, Doriate activates his Law of Retrogression Magic once again, this time turning not only Gray, but everyone in the Sun Village into kids.

Suddenly, Happy and Carla fall from the sky, having also been turned into kids. Seeing Doriate, the two Exceed wonder if he was the one who turned everyone into kids. As Doriate charges forward, Gray steps up to confront him and fires several attacks at him but finds that they are ineffective. Further attempting to eliminate his mobility by freezing his feet to the ground, Gray finds this fruitless as well as Doriate breaks free easily and subsequently delivers a powerful kick, sending the Fairy Tail Mage flying. Having taken heavy damage from the blow, Gray struggles to get up as he remembers what Doriate said about the Law of Retrogression's effects, noting to himself that Doriate is still getting stronger and if he takes another such hit he will be done for. As Doriate jumps at an immobile Gray, the child-bodied Mage attempts to think of a plan and remembers the surrounding ice in the village. Just as Doriate's fist is about to make contact with Gray, Happy and Carla carry the Ice Mage out of harms way, despite their limitations on flight keeping them close to the ground, something Gray notices.

Remembering that though his ice didn't directly hurt him, some frozen bushes did, Gray theorizes that the ice covering the village is Doriate's weakness given how he avoids it instinctively despite being a rampaging beast. Knowing that he needs to hit him with said ice, Gray narrowly avoids another hit while thinking of a plan. Remembering that the ice was reminiscent of Deliora, Gray realizes that his earlier failures to work with it were simply the result of his own intimidation and that he can now do it. Putting his hand on the ground, Gray prepares to use his own body as a vessel, thus shooting the ice of the village through his body at Doriate, thus defeating him and returning everyone to their normal bodies.

Aftermath
As the defeated Doriate himself reverts to his original form, Gray is approached by Happy and Carla as he wonders about the Magic, noting that while there has been no change in it, Doriate's demon form worries him more. At this, Doriate looks at Gray and begins laughing, telling him he opened the gates to the underworld and cannot close it just as he is eaten by a large monster, much to everyone's shock. As the monster turns its attention to the Fairy Tail Mages, the three of them quickly escape and make a run for it when the monster continues its pursuit. Eventually coming across their guildmates and Flare, Gray calls out to them while running. Unable to fight back due to lacking Magic Power at the moment, Gray is told that the giant mountain in the area is the Eternal Flame of the Village. Deciding to try and melt the ice in the area, Gray goes to do so while Natsu takes over the fight with the monster.