a long road

It is also strange to me that a non-Fiorean Gray would have known about Makarov/Fairy Tail to the extent that he would place his entire hope (remember, he initially goes to the guild to ask Makarov to undo Iced Shell) on a faraway wizard. Sure, Makarov is a wizard saint and likely famous. However, we have since come to learn that there is a ranking among the Saints which might explain it beyond the obvious answer (Gray needed to have heard about the guild and its master so that he could go to Magnolia and join the guild). There are just two issues: a. Makarov does not rank particularly high, able to be fifth spot at most and b. Makarov is not a dedicated ice magic user. If he was famously an ice user, it could be overlooked and even called logical—Gray would of course seek out another powerful ice user for answers.

However, due to what has already been outlined, this logic does not track. It simply does not exist.

Disbelief might be suspended if there was any main story mention of Gray having sought out more local mages that specialise in ice magic and that going to Makarov was a desperate last ditch effort, but there is nothing in the story that would convey the emotional distress of Makarov being the last resort. It is also just a touch strange that after travelling, allegedly, across continents and countries alike, Gray would just go 'oh okay' when a non-ice user tells him that undoing Iced Shell is impossible. Sure, Makarov is a wizard saint, but what exactly is his qualification to make a definite statement about Iced Shell? The only people we have ever seen use or try to use the spell are Ur and her students, adding to my theory that Ur created Iced Shell. Due to the circumstances, it would make more sense for Gray to take Makarov's word for it if he had not just vaguely heard of Makarov's magical prowess but if he had grown up in an environment where Makarov had been discussed more frequently.

So, here is a proposed and hopefully more logical sound explanation: like almost anything else in the manga, Deliora's attacks happened in Fiore. Probably along the border to Bosco which would account for a few things. The location where Deliora met its end is called Brago. The only thing really known about Brago is that it is not on the map that was shown at one point, early on. (It is also known that Mashima only really planned out Fiore and that the surrounding countries are just there to fill in the spot. Which is fine.) It is also supposedly in 'Isvan'. We later (much later) learn that the continent that Fiore is on is called Ishgar.

This following point is a bit of a stretch and admittedly based on my experience with FMA where the same location was called both Ishval and Ishbal, depending which FMA adaptation is considered, and Ishbar in the German Translation, but I think that those two places---Isvan and Ishgar---are the same thing which allows me to proceed without further ado, especially that all we know about Isvan is derived from one sentence Ur said---that there are more powerful mages west of her location---which seems to indicate that the location is in the east. If we assume that what Isvan equals Ishgar, then what she might have meant is that more powerful mages can be found in the more densely populated areas of Fiore where the guilds are.

One could spitefully say that this is supported by the fact that in the war that, according to canon, hit the entire continent, only Fiorean mages did anything remarkable that was worth any screentime.

Also---if Gray is from Fiore, a lot of plotholes close or are not even opened to begin with.

Note: I generally assume that most canon events take place in Fiore due to the aforementioned fact that pretty much every other place is terribly underdeveloped and I would hope that Mashima would have at least some idea about the place one of his main characters is from. (This does include my belief that the Magic Council is a Fiorean organisation that deals with Fiorean mages since otherwise, I envision it to be one gigantic mess as it is more or less canon that the Royal Family does not really have much to say about the mages living and working in Fiore. Which, uh, sure is a narrative choice that absolutely does not create messy legal situations!)

Why did he know about Fairy Tail/Makarov? Insert any explanation, ranging from a Fairy Tail mage having done work in his hometown prior to Deliora to Gray having read about them in the newspaper. Again: Makarov is a wizard saint. So is Jose Porla, of course, but to a child, Fairy Tail has to sound more appealing than Phantom Lord. And those two are the only wizard saints that are easily accessible to a child as they are guild masters and guilds (at least Fairy Tail) appear to be public spaces that can be entered by non-members.

To refer back to the earlier thought: that Gray might have heard of Makarov before. This really is not a stretch. Makarov is of course not going to show up in any publications like the Mage I Want To Be My Boyfriend ranking the way (I'm fairly sure) Siegrain did, but there is a canon interview that the Sorcerer Weekly magazine conducted with the entire guild. To think that Gray would have had access to newspaper articles or other publications does not seem like much of a stretch---he was born a mage, after all, and why would his parents keep him about information about other mages?

Why did he speak the Fiorean language? Well, he is from Fiore. It is generally doubtful if there are even multiple actively spoken languages in Earthland due to the fact that no matter where the characters go (and that includes a Mirror World), they can be understood and they understand others. The only character speaking a different language is Minerva when she calls upon the God of War. Then there is the script Freed uses for his magic, but I cannot recall if he or somebody else ever reads the script out loud.

A lot about Deliora, actually. The entire Deliora Plot that is witnessed during the actual manga also unfolds in Fiore. We can assume that Sherry's magic played a big role in getting Deliora to Galuna Island for the Moondrip Ritual, but even with that in mind, the entire story unfolds much smoother if Deliora was already somewhat in the vicinity of the island when Lyon started his plan.

His silence about his backstory. In a previous headcanon I said that one of the reasons why Gray and Natsu clashed as children was the very different way they dealt with their respective trauma. Natsu copes by telling everyone about Igneel---perhaps because saying it again and again helps him feel reassured that it was real, that despite what some adults say, it did happen. Gray copes by bottling his trauma about the deaths of his parents and Ur's sacrifice up. He cannot talk about it. He feels guilty* about his role in it. Makarov obviously has to know about where Gray is from and what the kid went through as Gray would have had to tell him in order to ask for help. I think Gray's silence becomes a lot more impactful and interesting if Deliora did happen in Fiore. If people around him know about the demon and heard the whispers about the end it met. If for ten years, Gray stewed in the knowledge that his choices spelled the end for someone who is now revered as a hero. As a saint.