Following Lucy's victory over Jackal, Gajeel spares her from the wrath of Torafuzar, however, he too is saved, this time from Keyes by Juvia. Just then, as Silver appears and threatens to freeze Juvia, Gray too arrives and cancels out his ice with his own, though he is visibly disturbed by the man's physical appearance. Now with no time to react, Tempester lands at the scene and attacks both Gray and Gajeel with a point-blank breath of flame; Natsu makes his entrance by eating the firestorm and thereby saving his comrades. With the immediate series of threats removed, Natsu states that he hasn't any idea as to what's happening, but that he feels as though Lucy has saved them from something. Now addressing the opponents before them, Natsu calls the line-up of extremely formidable opponents quite hospitable, and the Mages and Demons stare each other down, ready for battle.
However, before any sort of fight can begin, after Natsu notes that Tartaros' plan seems to have hit a snag, Gray's unease about Silver's appearance becomes apparent; Natsu explains that he's the one that froze the Sun Village whilst Gajeel, like Natsu earlier, says that Silver's scent is very similar to Gray's own, something which sends Juvia into a tizzy. With that, Silver rushes at Gray and then teleports the two of them to a new location, claiming that Gray is his to fight.
Landing outside in the remnants of Plutogrim, Silver informs Gray that Tartaros has summoned approximately three thousand Face bombs, which causes Gray to wonder what the Magic Council was thinking when they made the device. Questioning whether that was all Silver wanted to tell him, Silver responds that he wanted to see Gray in despair; declaring that he doesn't despair very easily, Silver expresses his disappointment in the fact. Hearing that Silver wants to kill him, Gray asks if he knows about him, which Silver answers he does, and rather well at that. Unnerved, Gray says that he knows Silver all too well as well: his face and his voice; however, he adds that they belonged to someone else and demands to know who exactly Silver is.
Gray then proceeds to ask who Silver is, to which he is told that he is his father, which Gray refutes as he watched his father die, however Silver merely replies that he is Silver Fullbuster: his father. Enraged, Gray calls Silver's statement a lie and shoots ice at him, which is effortlessly deflected. He immediately follows up by trying to land several hits, but his efforts are deemed pathetic and he is merely thrown back, repeatedly. As this occurs, Silver laughs at Gray thinking that his father is dead and cites Gray's angry face as one he has always imagined. He then goes on to explain that the part about him being his father is true, but states that things get more complicated. Adding to Gray's confusion, Silver says that he and Gray are part of a much greater existence and that they are destined to fight.
Curious, Gray attempts to attack Silver and try to find out what he means, but Silver bats him away and begins by explaining that the body he is using is a vessel; a corpse he found lying around. Adding that all the members of Tartaros are Demons from the Books of Zeref, Silver says that his original form is far from human. Stating that he uses a human form as a having a demonic body is rather inconvenient, Silver says that he happened across it by chance and has been using it ever since, though he adds that the body he has simply draws them together in more ways than one. Finishing that he's been waiting for the day when he could kill Gray with his own hands, Gray yells at Silver, telling him to stop messing with him and that, unlike himself, he has no reason to hate him. Sinisterly smiling, Silver says that Gray is wrong and mentions that he isn't satisfied with killing just Ur. Revealing himself to be the Demon Deliora, Silver inquires as to whether or not Gray has forgotten him.
Taken aback, Gray remembers when Ur sacrificed herself to kill the Demon and calls it impossible, citing that his death happened over ten years ago; Silver admits this, but explains that Tartaros has a regeneration facility. When Gray asks whether he really is the same Deliora, Silver counter-questions whether Gray wants to see the same form he used when he killed his family, which causes him to snap. Now livid, Gray charges at a laughing Deliora in an attempt to finish what his teacher started.
Initiating the true conflict, Gray charges at Silver (whom refers to Gray as Ur's remnant), screaming his Demon form's name, and attacks with ice, which Silver easily dodges and redirects, almost impaling Gray with his own ice. Gray dodges, but Silver appears in front of him and blasts him away with a burst of his Devil Slayer Magic. Being blown out of the ruins, Gray creates a series of platforms for him to jump back into to battle with. Jumping up into the air, Gray tries to slice Silver with his Ice-Make: Cold Excalibur, but Silver catches the giant blade between his two hands and laughs before eating the ice. Sighing, Silver reminds Gray that elemental Magic doesn't work on Slayer Mages of the corresponding element and then laughs again; he explains that Ur's disciples only learned Ice Magic, so in response he learned Magic which made him resistant to ice. Immediately after, Silver impales Gray with large shards of ice and maliciously laughs, screaming that after he's done with Gray, he'll kill Lyon, and then finally all of his friends. Angered with his father's face and voice being used in such a manner, Gray unleashes Ice-Make: Ice Impact to try and do some damage, but Silver simply eats his ice once more and counters with his Ice Devil's Rage, releasing a blizzard from his mouth that sends Gray reeling.
As Silver laughs at him, Gray remembers his father telling him to be strong and rises from the ground, promising to kill him with his very hands, however Silver replies that ice is ineffective and that Gray's chances of winning are less than zero. Creating a cannon, Gray fires rubble at Silver, which proves to be effective as he cannot eat rubble. After firing a barrage of rubble, Silver swipes his hand and freezes the area, thereby preventing Gray from repeating his strategy. Gray, though, smiles and tells Silver that he's dug his own grave, as he can pass the ice, which covered the Sun Village, through his body and recreate it into any form he desires. Citing that there's an exception to a Slayer Mage's ability to devour their elements (they cannot eat their own), Gray fires a torrent of Silver's own ice at him; though he is heavily damaged, Silver is not defeated and says that even if he can't eat his own ice, ice is still ineffective against him. Walking forward, Silver asks a perturbed Gray if he has remembered the terror of Deliora.
Beating Gray away, Silver asks if he lost his nerve and continues to viciously beat him, sadistically screaming for Gray to keep on scowling. He adds for Gray to learn terror and asks how he could dare to stand before catastrophe itself and think he could win; blowing him away with ice, Silver asks if Gray thought he could turn his anger into strength and tells him to remember the taste of despair, as well as that humans can never defeat Demons. Bloodied, Gray rises and tells Silver that he doesn't care, and that he must win no matter what, however, Silver counters that ice is ineffective against him and that he has prevented Gray from attacking him physically, as well as adding that he's not soft enough to grant an appeal because of emotion. Undeterred, Gray says that he has a trump card and assumes the position for Iced Shell.
Taken aback, Silver tells Gray to stop bluffing, as Iced Shell will cost him his life to use, as well as adding that Ice Magic doesn't work on him, but Gray counters that it worked over ten years ago when Ur froze him; Silver says that was before he learned Ice Devil Slayer Magic, which prompts Gray to comment that Silver should be able to survive his attack. With Silver that he will die if he continues, Gray screams that he's going to surpass Deliora and begins casting Iced Shell, prompting Silver to back away and attack Gray, however he merely attacks a clone. The real Gray appears behind Silver and remembers when Natsu stopped him from using Iced Shell the first time, as well as all his friends, and says sorry before casting Iced Shell; Silver screams in fear but ultimately overcomes Iced Shell, breaking the spell. The Gray that cast Iced Shell is then revealed to be a clone as well, and the real Gray again appears behind Silver and tells his friends that he's sorry for almost throwing his life away. Stating that he refuses to die, Gray grabs a steel ball from the rubble, explaining that like in the Sun Village he unfroze the ice, and casts Ice-Make: Vambrace, throwing the steel ball at Silver with immense force. The ball tears through his chest and Silver falls to the ground, smirking and praising Gray's work.
Gray, panting heavily, asks Silver if he believed that he wasn't going to realize the truth; asking what Silver was thinking, Gray states that the man isn't Deliora the Demon at all and says that Silver is, in truth, his real father, which causes Silver to sorrowfully look into the sky.
Silver tells his son to finish him off, but Gray adamantly refuses; Silver explains that he's been waiting for Gray to kill him as he is no longer human nor Demon: he is a corpse that was revived by Keyes' Necromancer Curse. He was used in an experiment, and unlike the other corpses, his desire for revenge, the desire to destroy every Demon that ever existed, kept him existing. Revealing that he killed Demons in secret while in Tartaros, Silver apologizes for the Sun Village, as the flames weren't demonic. Continuing on, Silver explains that he was about to destroy Tartaros when he learned that Gray was alive and that he had no right to fight for his or Mika's sake, as his hands were too stained.
Gray inquires as to whether or not that that's why Silver wants to die, but he corrects him, saying that he's already dead and wants to disappear, opting to leave everything to Gray. Gray shouts that it's not up to him to do so, but Silver merely says that Gray doesn't need to do anything and apologizes for his words and actions; Gray realizes that Silver acted the way he did so that Gray could sort out his inner turmoil, while Silver simply tells Gray that he's better off forgetting him, as his dad died long ago. Stating that he's wrong, Silver says that no father would ever hit his child and begs for Gray to finish him, and although Gray creates a sword for the job, saying that he must eliminate threats to Fairy Tail, he drops his weapon and cries, screaming that he can't kill his own father. At this, Silver rises and hugs his son, telling him that he's grown into a fine man and that he is his and Mika's pride and joy.
As this occurs, Silver telepathically contacts Juvia, whom almost immediately recognizes him as Gray's father (and becomes immediately flustered when Silver mistakenly identifies her as being Gray's girlfriend), and tells her to destroy Keyes so that she can stop the deceased Chairman, Crawford Seam, from activating Face, however, she catches on to the fact that if she goes through with his plan then he will disappear as well and Silver, after praising Juvia for her wit, tells her that she must kill Keyes regardless, as everything is for Gray's sake. Ultimately, though, Juvia manages to kill Keyes and Silver is released from the necromancer's curse; as he disappears, he thanks Juvia for freeing him and stopping Face, and also tells her to not say a word and take care of Gray, which she sorrowfully agrees to do. With his dad now gone, Gray tells Silver that he can rest in peace and listens to his dad's final message: E.N.D. is a fire Demon and is the reason why he learned Ice Devil Slayer Magic. Now having been bestowed his father's Devil Slayer Magic, Gray holds out his now-tattooed right arm and claims that as an Ice Devil Slayer, he's going to destroy E.N.D.