(Re)defining Special, Legendary & Mythical Pokémon (Sun & Moon spoilers!)

[TouyaShiro]

So, as we all know, Legendary Pokémon exist everywhere in the Pokémon universe. From Mewtwo to Xerneas, Cosmog to Zapdos, and everything in between, there's a wide variety of powerful Pokémon from all regions considered to be Legendary Pokémon. Some people don't like them, some people do, and that's all well and good - however, that's not what I'm here to talk about today. Our topic of discussion is Generation VII - and how it may have changed everything about what we know about the definition of a Legendary Pokémon.

First, before we move on, let's remind ourselves of the current definition of a Legendary Pokémon and a Mythical Pokémon, courtesy of Bulbapedia:

Legendary Pokémon (Japanese: 伝説のポケモン Legendary Pokémon) are a group of incredibly rare and often very powerful Pokémon, generally featured prominently in the legends and myths of the Pokémon world.

Mythical Pokémon are a related but separate group of Pokémon, which are usually event-exclusive. Prior to Generation V, Mythical Pokémon were considered to be Legendary Pokémon in non-Japanese media.

Legendary Pokémon - Bulbapedia, the community-driven Pokémon encyclopedia

Mythical Pokémon (Japanese: 幻のポケモン Illusory Pokémon) are a group of Pokémon seen so rarely in the Pokémon world that some question their very existence. These are event-exclusive Pokémon that cannot be obtained during normal gameplay,[1] with the exception of Deoxys.

In Japanese media, Mythical Pokémon and Legendary Pokémon have always been presented as distinct groups. In non-Japanese media prior to Generation V, Mythical Pokémon and Legendary Pokémon were both considered to be Legendary Pokémon (and the term Mythical Pokémon was unused); in non-Japanese media from Generation V onward, the two groups are presented as distinct groups. In Pokémon Ranger: Guardian Signs, Mythical Pokémon are referred to as rare Pokémon.

Mythical Pokémon - Bulbapedia, the community-driven Pokémon encyclopedia

Standard stuff thus far, and well understood by the majority of Pokémon players around the world. Let's return to that in a moment.

So, as you might have heard, Pokémon Sun & Pokémon Moon have their own special Pokédex model, with a couple of special features aside from being inhabited by a Rotom this time around. While the list of features does not include a National Pokédex upgrade of its own, here's a few of the features of the Rotom Pokédex:

• Every Pokémon's entry is registered no matter how you obtained them, be it trade or evolution or any other method. Rotom comments on them depending on how you obtained the entry as well as commenting on any milestones in Pokédex completion!
• Four Pokédex sections exist which cover all of Alola's islands, and the greater Alola Pokédex encompasses 300+ Pokémon in total - similar to the Kalos Pokédex being split into three sections for Central, Coastal and Mountain Kalos.
• QR Codes can be shown for every single Pokémon in the Pokédex, except for a select few - though these Pokémon do have QR Codes programmed in. It's done this way to allow the possibility of including these QR Codes on merchandise for you to scan with your game and 3DS.
• Instead of the professor, Rotom can evaluate your progress for you! No need to go to their lab or check the PC, and they can evaluate your single Pokédex or the entire Alola Pokédex.

However, there's one feature which is highlighted for you every time you register one of them in the Pokédex - a different noise, a more flashy effect for the word "REGISTERED" occurs, and a different background colour accompanies certain Pokémon when you catch them - and certain ones even have a holographic effect applied which moves with the built-in gyroscope on the 3DS. Rotom has a special comment for these Pokémon depending on whether it's a Special Pokémon, a Legendary Pokémon or a Mythical Pokémon.

Wait, what's a Special Pokémon, you ask? Well, let's read Bulbapedia's definition thus far:

Special Pokémon (Japanese: 特別なポケモン Special Pokémon) is a term referring to a group of Legendary Pokémon in the core series games and side games that are restricted or banned from certain official tournaments, battle facilities, and link battle formats. Most of the Special Pokémon are game mascots (but not all game mascots are Special Pokémon). While the concept exists in all generations, the term was not used until Generation IV.

Whenever special Pokémon are restricted or banned, Mythical Pokémon are banned. While often only special Pokémon are mentioned to be banned when both special Pokémon and Mythical Pokémon are, the description of the GS Cup indicates that Mythical Pokémon are not special Pokémon.

Special Pokémon - Bulbapedia, the community-driven Pokémon encyclopedia

Now here's where things get complicated. Let's list the type of background and comment Rotom can make whenever you register a Pokémon:

• Normal Pokémon - blue background. Rotom provides a standard comment. This changes depending on how you obtained the Pokémon and therefore register the new entry in the Pokédex - trades, evolution, catching, gifts, it's all covered.
• Powerful, special Pokémon - green background. Rotom provides a unique comment about unidentified species if you catch an Ultra Beast, saying it's indescribable but amazing if you register Type: Null and directly mentions the category of the Land Spirit Pokémon should you happen to catch one of the tapu.
• Legendary Pokémon & Mythical Pokémon - gold background & holographic effect. Rotom comments on every Legendary Pokémon registered, saying that it's, well, legendary! If you instead register a Mythical Pokémon, the Rotom inside stutters a bit in amazement at something so rare.
• All of the above can also be accompanied by comments from Rotom about any milestones you make in terms of your Pokédex progress.

So, the reason this gets complicated are the sections regarding Special Pokémon and Legendary Pokémon - as the definition bounces a couple of times in the Pokédex itself. Referring to the above definition of Special Pokémon and their restrictions in battle facilities and official competition, Pokémon who are clearly legal for use in things like the Battle Tree include Silvally, the Ultra Beasts and the four tapu. All of them say this if you attempt to reveal their QR Code in the game itself:

This is a special Pokémon.
There is no QR code.

Note, however, that the word "special" isn't capitalised. This same message shows when you attempt to view the QR Code of a Legendary Pokémon or Mythical Pokémon, without modification. Does this mean that the term of Special Pokémon is changed? Probably not - the game's own rulesets, those that are downloaded from Festival Plaza, and the ones set by Friendly Competitions have a Special Pokémon filter which are set to Permitted or Banned, and the usage of this filter is in line with previous Generations - banning Pokémon such as Zygarde, Necrozma and even Cosmog and Cosmoem despite their uselessness in battle.

However, there's also a point of debate regarding all the Pokémon that were given a green background in the Alola Pokédex. The game explicitly shows you when a Legendary Pokémon is being registered in the Pokédex, and since they don't actually state as such with Pokémon that have a green background, there's been a bunch of talk about whether or not things like the Ultra Beasts and the tapu are even considered Legendary Pokémon under the definition that we've come to know and accept in the Pokémon community. After a while of this talk, I had a thought which I talked about a few times on Discord - whether or not Game Freak would retroactively apply this same system to all the other Legendary Pokémon of the past Generations.

Fast forward to January 25, 2017. Pokémon Bank finally receives its long-awaited update that adds compatibility with the Generation VII titles, and Generation I titles via Poké Transfer to Generation VII games, while maintaining the compatibility with Generation VI. It also added a new Pokédex feature in lieu of a proper National Pokédex for Sun & Moon, which updated with every game you used with Pokémon Bank to create a collective and massive National Pokédex for you to look at. Though it doesn't include any 3D models for you to look at, a snapshot of every Pokémon and every form they have, all their cries, every single Pokédex entry for that specific Pokémon (which you can switch between by tapping that game's icon on the touch screen) and incorporation of many different Pokédex filters - including "Good Old Hoenn" for Generation III's Hoenn Pokédex - make it one of the most robust and comprehensive Pokédexes out there. This Pokédex incorporates the upgrades seen on the Alola Pokédex, and though it cannot be displayed in the same manner, it makes the same distinctions between special Pokémon, Legendary Pokémon and Mythical Pokémon, displaying a different but similarly functioning holographic effect for any registered entries involving the latter two that overlays the part of the icon which displays that Pokémon's type, and moving with the gyroscope on your 3DS.

When I went to look at it later, it turns out that the hunch I made a while back actually came true - looking back on Pokémon from Generations long gone, several of them have been revoked of Legendary Pokémon status and do not display the holographic border like one would have expected before. Among them, and including Generation VII's own green background Pokémon, they include:

• Articuno, Zapdos and Moltres
• Mewtwo (!!)
• Raikou, Entei and Suicune
• Regirock, Regice and Registeel
• Latias and Latios
• Uxie, Mesprit and Azelf
• Heatran
• Regigigas
• Cresselia
• Phione
• Cobalion, Terrakion & Virizion
• Tornadus, Thundurus and Landorus
• Type: Null and Silvally
• Tapu Koko, Tapu Lele, Tapu Bulu and Tapu Fini
• Nihilego, Buzzwole, Pheromosa, Xurkitree, Celesteela, Kartana and Guzzlord

Of all the things on the list, Mewtwo's status is downgraded. I can't tell if that's an error or if that's deliberate. Groups in that list which have a Mythical counterpart or companion, such as Cresselia and the Swords of Justice, have their Mythical bretheren marked just as Legendary Pokémon are - so that much hasn't changed a single bit (and, as pointed out by @Esserise below, the same restrictions apply to Phione despite not having the same holographic frame as the other Mythical Pokémon).

However, if we look at the existing list of Legendary Pokémon that are not part of that list above, they all share a couple of things in common - most of them are the mascots of their respective games, and are very heavily tied into the mythos of the region they come from, and in most cases it's central to the plot of the game itself. For those that are not, this was either rectified in a third version, or made ambiguous - what this means for Zygarde and Necrozma, who do not have a game of their own, nor are tied to the main legends of their respective regions, is not known at this time.

So, does this mean that Game Freak are making an attempt to redefine what it means to be a Legendary Pokémon? Perhaps they want to make it a bit more indicative and fully literal. Do you agree with the changes? Is there an aspect to the story that I'm missing? Please, by all means, let me know below and vote in the poll above. This is something that's been on my mind for a long while and I've only just now - amongst all my other distractions - finally gotten the chance to write about it.

Those who work on the wiki itself are gonna have a field day with this one, I can tell you that much...

 

[Esserise]

Well firstly I'm not sure I can answer the poll question without a clear consensus on what exactly the "new definition" is.

Secondly, I remember looking through my Bank Dex a few days ago, and I am 99% certain that the lake and musketeer trios did NOT have holographic frames, and that Phione also did NOT but Manaphy DID. If someone doesn't beat me to it, I'll try to look at it again later today in order to verify, if I have time.

EDIT: Confirmed. Manaphy has a holographic frame. Phione, Uxie, Mesprit, Azelf, Cobalion, Terrakion, and Virizion do not. Also, while it may be tempting to view this as proof that Phione is not considered Legendary/Mythical, it should be noted that it is still banned from the Battle Tree, like all Special and Mythical Pokémon.

Anyway, I'm not really too fussed about what's classified as Legendary or not, I'd just like for the criteria to be certain. The other day when I was looking at my Bank Dex, I started to wonder why I'd been reluctant to consider Type: Null and Silvally as Legendary Pokémon. Silvally has the stats for it, and Cosmog shows that evolution is possible for Legendary Pokémon. The fact that they're artificial shouldn't really matter, because Mewtwo is a human creation as well, and both it and Silvally are derived from Mythical Pokémon in some way. Actually, in both their cases, "Legendary" would be a misnomer anyway - neither Mewtwo nor Silvally exist in any myths or legends, because they are recent inventions. I suppose there could be prophecies, since psychics do exist in-universe, but thus far we've been given no reason to think that anybody foretold the coming of either Mewtwo or Silvally.

(Genesect is subtly different here - it could potentially be a figure that appears in myths, it's just that the only one we ever see is encased in modern manmade armor. In XY, a Hiker mentions that there are rumors of Genesect appearing in Glittering Cave, and I highly doubt that he's referring to more cybernetically-enhanced versions.)

I know that I don't see much of a point in classifying the Ultra Beasts as Legendary Pokémon. They already have their own distinct umbrella to fall under, and don't follow the laws and logic of the main dimension anyway. Our terms are pretty much meaningless to them. Although there are old stories about Nihilego, so if we use the literal definition of "legendary" that disqualifies Mewtwo and Silvally, Nihilego would indeed be "legendary" in that sense.

Given that the "lesser" Legendary Pokémon have always been referred to as Legendary Pokémon in past games, I'd be more likely to assume that they haven't been "demoted" so much as reclassified as a different kind of less-remarkable Legendary Pokémon. If only to avoid the headache of things like Platinum telling me that Zapdos and Heatran are Legendary Pokémon while SM tell me they're not. Maybe the lesser ones are "legendary," while the ones with top billing are "Legendary."

(In a weird way, I kind of like that they've contradicted themselves. At least now it's not just Phione that has to deal with this.)

 

[TouyaShiro]

That is a curious thing to think about, haha. It's a matter of considering whether or not they always considered them to be lower than the "proper" Legendary Pokémon, but for my money I think it's more likely that - with the abundance of Legendary Pokémon in Generations prior - they want to move with a new way to categorise them moving forward, and retcon the ones from the past, even if it leads to situations like the above where you mentioned Pokémon Platinum, Zapdos and Heatran. Part of me thinks it has to do with how few Legendary Pokémon actually exist in Kalos, of which there is a grand total of three; all of them being similar in design and linked to one another, be it vaguely or explicitly, as opposed to some past Generations which introduced a ridiculously high amount of them.

Perhaps one of the motivations for Game Freak to pull for this is to make the term of "Legendary Pokémon" have a bit more meaning - I know I've seen people complain about how they used to be super secret things, the biggest thing in terms of your Pokédex for bragging rights, and that later Generations - IV and V in particular - may have ruined their perception of that meaning. With that said, I will admit that they've not said anything about this quite yet, and you're definitely right to point that out. We can't know for sure whether or not this was their intention.

For the above distinction between Cosmog and Silvally, I'd argue that Cosmog's status as Legendary despite its combat uselessness is entirely to do with the fact that it evolves into the Legendary Pokémon spoken of in Alola's myths and libraries, and that it'd receive that classification in the Pokédex purely by association from evolving into Cosmoem, and then into Solgaleo/Lunala. I don't have much comment on the other side of the matter for Silvally right now.

For the UBs, it's true that they have an umbrella that they fall under - but, while I'm not a person who personally would argue this point, it's possible that a few people could argue that it matches other such groups like the Forces of Nature who are a similarly powerful, named group of Pokémon which have their own separate origin and mythos in their region. While we don't know the true name of every single group of this category, it'll be interesting to see how they use this in future Generations.

The Genesect point you raise is rather interesting to think about. I might have to look into that later...

By the way, @Esserise, thanks for your help! The OP has been updated.

 

[Silktree]

Well, at least this explains the classification of the Tapus even though they're clearly tied to Alola myths. More so than Solgaleo and Lunala, arguably.

Mewtwo's classification makes sense lore-wise, but it certainly stands out on that list. I should note that Deoxys, Darkrai, Genesect and Volcanion (and the list goes on) being classified as mythicals doesn't necessarily make them more legendary than Mewtwo. Most mythicals are pretty... unremarkable lore-wise.

The only thing that bothers me is the lack of an official category for these "not quite legendary" Pokemon. Unown should be there, but I wouldn't even include Phione in it, as it's utter trash.

 

[Ash_Pokemaster]

There is a very simple pattern on what has received a special background and what hasn't: only mascot Legendaries, Mythical Pokémon, and Zygarde have. I was just looking at this the other day, and my conclusion is that the National Pokédex is a terrible classification mess, not an attempt to introduce new definitions.

The practice of special backgrounds is certainly a good opportunity for them to clear a few things up, but they didn't make good use of it. Personally, I think there should be four tiers:

• Mythical Pokémon
• Mascot Legendary Pokémon: Mascots, Mewtwo, and Zygarde
• Legendary Pokémon: All other traditional Legendary Pokémon, Silvally?, Ultra Beasts?
  
• Rare Pokémon: Unown, Phione?, Cosmog/Cosmoem, Type:Null, Guardians?

I'm not entirely sure about what should be done about UBs and Guardians. They certainly are a bit out there. One option would be to introduce a fifth tier between Mascot and Legendary: "Powerful" Legendary Pokémon, perhaps including the Eons, Regigas, and the UBs, and putting Guardians under regular Legendary, which they honestly feel like. But this feels unnecessary, and the Guardians could instead kickstart the whole concept of "Rare" Pokémon, essentially semi-Legendary.

Phione could be a Rare, but I think classifying it as a normal Pokémon would be more accurate lore-wise, as per Carbink. In any case, its inclusion in the Rare category would contribute in the definition of that category as the one where Pokémon related to actual Legendaries (via evolution, lore, or otherwise) belong.

 

[Esserise]

That is a curious thing to think about, haha. It's a matter of considering whether or not they always considered them to be lower than the "proper" Legendary Pokémon, but for my money I think it's more likely that - with the abundance of Legendary Pokémon in Generations prior - they want to move with a new way to categorise them moving forward, and retcon the ones from the past, even if it leads to situations like the above where you mentioned Pokémon Platinum, Zapdos and Heatran. Part of me thinks it has to do with how few Legendary Pokémon actually exist in Kalos, of which there is a grand total of three; all of them being similar in design and linked to one another, be it vaguely or explicitly, as opposed to some past Generations which introduced a ridiculously high amount of them.

I should have thought of this earlier, but it's definitely worth pointing out: At the Geothermal Power Plant in SM, there's an exhibit on the Kanto Power Plant, and part of it says this:

"This power plant was abandoned for a time, but the Legendary Pokémon Zapdos was said to have revealed itself to mankind there once."

So, no demotion there, at least.

Perhaps one of the motivations for Game Freak to pull for this is to make the term of "Legendary Pokémon" have a bit more meaning - I know I've seen people complain about how they used to be super secret things, the biggest thing in terms of your Pokédex for bragging rights, and that later Generations - IV and V in particular - may have ruined their perception of that meaning. With that said, I will admit that they've not said anything about this quite yet, and you're definitely right to point that out. We can't know for sure whether or not this was their intention.

I could see that, I guess, even though I've never agreed with the argument that the number of Legendary Pokémon in Gens 4 and 5 makes them feel "less special" or whatever. The way I see it, at least those Legendary Pokémon actually have some stories about them. All of Unova's Legendary Pokémon have a decent amount of backstory. I'll grant that there are some Sinnohan ones they could have done more with, but the idea itself of having lots of Legendary Pokémon in a region that's rich in mythology wasn't bad in of itself.

For the above distinction between Cosmog and Silvally, I'd argue that Cosmog's status as Legendary despite its combat uselessness is entirely to do with the fact that it evolves into the Legendary Pokémon spoken of in Alola's myths and libraries, and that it'd receive that classification in the Pokédex purely by association from evolving into Cosmoem, and then into Solgaleo/Lunala. I don't have much comment on the other side of the matter for Silvally right now.

I was really only bringing up Cosmog because normally, "it evolves" could be argued as a disqualifying factor for counting Silvally as a Legendary. You can substitute "Cosmog" for "Solgaleo/Lunala" all the same; they're still the end result of an evolutionary chain which shows that Legendary Pokémon can evolve, and therefore that cannot be held as a point against Silvally.

For the UBs, it's true that they have an umbrella that they fall under - but, while I'm not a person who personally would argue this point, it's possible that a few people could argue that it matches other such groups like the Forces of Nature who are a similarly powerful, named group of Pokémon which have their own separate origin and mythos in their region. While we don't know the true name of every single group of this category, it'll be interesting to see how they use this in future Generations.

I suppose people could make that argument, but I woudn't find it very compelling. Trios with their own lore have been contributing to the category of "Legendary Pokémon" since literally the beginning. If one were to argue that trios are distinct from Legendary Pokémon, then, well, one would end up dismantling the category of "Legendary Pokémon" altogether, since most of what are recognized as Legendary Pokémon are a part of a trio.

The UBs are sort of a different affair. Theirs no overarching theme to them other than being bizarre aliens from another dimension. There's no parallelism or even interaction between them. "Ultra Beast" is almost like a broad category unto itself, wherein the variation begins on the individual level of each UB.

By the way, @Esserise, thanks for your help! The OP has been updated.

No problem.

 

[Silktree]

If they call Zapdos a legendary in SM, which they don't with the Tapus, then I am not going to read into borders. They need to step up and give those trios a different named classification if they've actually changed their mind...

 

[TouyaShiro]

There is a very simple pattern on what has received a special background and what hasn't: only mascot Legendaries, Mythical Pokémon, and Zygarde have. I was just looking at this the other day, and my conclusion is that the National Pokédex is a terrible classification mess, not an attempt to introduce new definitions.

The question at that point is, why does the Pokédex not say so? I've already mentioned how explicitly Sun & Moon points out to you every Legendary Pokémon you've registered in the Pokédex, and none of the green background entries say that. Unless we get clarification from Game Freak or TPCi on this, we could probably go back and forth on trying to figure out the truth without going anywhere.

Of course, then we receive things like the above thing @Esserise points out in the Geothermal Power Plant. Just what are they trying to do here, exactly? I'm not sure if I want to actually take a side here in the debate, aside from agreeing that Game Freak has kinda thrown everything we know out of wack. The only thing I'm sure of is that we're probably gonna see the powerful/Legendary Pokémon groups be made like the ones in Alola are from here on out, should the series itself continue beyond Generation VII (which there may be no doubt of, of course, but we're still a few years away from that point so it's a way early speculation).

The practice of special backgrounds is certainly a good opportunity for them to clear a few things up, but they didn't make good use of it. Personally, I think there should be four tiers:

• Mythical Pokémon
• Mascot Legendary Pokémon: Mascots, Mewtwo, and Zygarde
• Legendary Pokémon: All other traditional Legendary Pokémon, Silvally?, Ultra Beasts?
  
• Rare Pokémon: Unown, Phione?, Cosmog/Cosmoem, Type:Null, Guardians?

I'm not entirely sure about what should be done about UBs and Guardians. They certainly are a bit out there. One option would be to introduce a fifth tier between Mascot and Legendary: "Powerful" Legendary Pokémon, perhaps including the Eons, Regigas, and the UBs, and putting Guardians under regular Legendary, which they honestly feel like. But this feels unnecessary, and the Guardians could instead kickstart the whole concept of "Rare" Pokémon, essentially semi-Legendary.

Phione could be a Rare, but I think classifying it as a normal Pokémon would be more accurate lore-wise, as per Carbink. In any case, its inclusion in the Rare category would contribute in the definition of that category as the one where Pokémon related to actual Legendaries (via evolution, lore, or otherwise) belong.

Interesting proposition. Not sure if I 100% agree with the way you sorted out your proposal, but by all means I think it's a good start and point of discussion. Knowing Game Freak, though, Phione would still be categorised normally because they're still not sure, lol. I think it's worth noting that Pokémon Bank does not make the distinction of normal Pokémon and the "green background" Pokémon by itself (which is most easily seen if you use the Alola Pokédex sorting option), and that to find out which Pokémon fall under that banner, we had to look at our data from the past about previously known Legendary Pokémon and see which ones didn't have the holographic frame. It's unlikely they'll add that sort of thing in a future update, to distinguish the currently existing 3 categories in Bank itself.

I was really only bringing up Cosmog because normally, "it evolves" could be argued as a disqualifying factor for counting Silvally as a Legendary. You can substitute "Cosmog" for "Solgaleo/Lunala" all the same; they're still the end result of an evolutionary chain which shows that Legendary Pokémon can evolve, and therefore that cannot be held as a point against Silvally.

True, true. It's funny to think about considering they were introduced in the same Generation - showing something that was previously thought impossible, and in the prerelease, may not have actually been considered to be powerful or Legendary and just be a rare Pokémon in general - and then, in the game itself, showing it to you again for those who didn't spoil themselves with the leaks by means of Nebby's evolution in the story proper... Though even if you had doubts at that point, picking up a Cosmog for yourself would allow you to properly see its evolution for yourself. (Or stick an Everstone on it for its entire lifetime, you heartless being.)

I suppose people could make that argument, but I woudn't find it very compelling. Trios with their own lore have been contributing to the category of "Legendary Pokémon" since literally the beginning. If one were to argue that trios are distinct from Legendary Pokémon, then, well, one would end up dismantling the category of "Legendary Pokémon" altogether, since most of what are recognized as Legendary Pokémon are a part of a trio.

The UBs are sort of a different affair. Theirs no overarching theme to them other than being bizarre aliens from another dimension. There's no parallelism or even interaction between them. "Ultra Beast" is almost like a broad category unto itself, wherein the variation begins on the individual level of each UB.

I will admit, since the UBs themselves are obviously otherworldly and much different to the Pokémon we are familiar with, it makes me want to see if they come up with more of them in Generations beyond VII's own, and perhaps give a passing nod to that game's plot when you catch it or something. The real kicker would be if it actually shared all of its traits with the others, such as the prime number base stats and the levels they learn moves at, in addition to Beast Boost and the signature sound effect they all share in their cries.

If they call Zapdos a legendary in SM, which they don't with the Tapus, then I am not going to read into borders. They need to step up and give those trios a different named classification if they've actually changed their mind...

Really, I just want a word from Game Freak to know what they were thinking - and whether or not we're thinking about this right or wrong!

 

[Ash_Pokemaster]

I think the right way to look at things is compare what we know with what is presented in the Generation VII Pokédex. The Legendary birds are not only inexplicably Legendary, but are the Legendary Pokémon, more so than Mewtwo, which may not have been intended to be considered a "Legendary", as far as the series semantics / terminology during Generation I is concerned. My understanding is that "Legendary Pokémon" as a term, or as an out-of-universe classification, was only consolidated after the first generation. Mewtwo, and by extention Lugia / Ho-Oh, were regarded Legendary as a comparison to the Birds, which were originally "legendary" from a canonical standpoint, ie. Pokémon spoken of in legends.

So, to answer the question you posed, the Pokédex doesn't say so because it's unreliable. Game Freak's decisions regarding the National Pokédex in SM are questionable to begin with, so, this is not a surprise. They likely didn't think through the whole thing very much, but nonetheless I have no doubt they had no intent to change the definition of Legendary Pokémon, much less "retcon" some of the most iconic ones out of their status. What they did actively pursuit however, is introduce classes of Pokémon that don't fit well with existing conventions: the Guardians, UBs, and Type:Null / Silvally. So, you are more than justified to bring up the question of Legendary classification, because things may get a little blurry moving forward.

If we're being honest, the Guardian deities are like any regular Legendary group. Their role and lore status isn't essentially different from, say, the Lake guardians. Ultra Beasts on the other hand, I guess we must wait and see. If they are a concept Game Freak wants to explore further in the future, it may be fair to consider them a new class of Pokémon, apart from Legendary. That would leave us with Mythicals, Special Legendaries, regular Legendaries, and Ultra Beasts. Type:Null / Silvally's status and future treatment remains a big question.

 

[TouyaShiro]

For the first paragraph, I think that's a point where you and I differ in perception - I hadn't figured out the concept of Legendary Pokémon for a long time until I started getting into the series more, and by that point HeartGold and SoulSilver were out - Everyone knew at that point that Mewtwo is basically the first thing you'd think of in terms of a Legendary Pokémon for the Kanto Pokédex. It's the iconic character, the (sympathetic) villain of the first movie, a badarse in general (even if he performs like crap in Melee) and all round a very powerful force in a large majority of games it's present in - and even if it's outclassed (such as Mega Rayquaza), it's the one people most recognise. The way I saw Kanto and its group of 4 Legendary Pokémon that you could catch in the game was that, for the most part, it seems like it was mostly just rumours and the like circulating in Kanto about their existence - the same boat Mewtwo was - and for a while, I'd imagine that was also the case for actually spreading the word about their existence in the game amongst players. Of course, my memory of the Generation I games are fuzzy, but to me it just doesn't seem like the Kanto region had "legends" and a mythology to speak of until Johto came around and retroactively applied one to the legendary birds. That, of course, came in the form of Lugia and its backstory as their trio master, but I never really heard of Kanto itself talk about the individual birds that much in terms of legends - at least, not in the likes of the story applied to the rest of the Legendary Pokémon these days, where the existence of these Pokémon is either much more well known or ties into the region itself a lot more than how it was back when Pokémon wasn't sure if it would even get up on its own feet.

So, to answer the question you posed, the Pokédex doesn't say so because it's unreliable.

20 years is a long time (and hey, it could still be 5+ years in chronology if you cut out all the waiting time between the games' release dates) and the Pokémon world could have changed perception just like we do in that timeframe. Granted, it's not the only possibility, but it wouldn't be the first time they've done something that could theoretically make the older Pokédex data "unreliable" - just look at Fairy types.

What they did actively pursuit however, is introduce classes of Pokémon that don't fit well with existing conventions: the Guardians, UBs, and Type:Null / Silvally. So, you are more than justified to bring up the question of Legendary classification, because things may get a little blurry moving forward.

This point I definitely agree with, except for one thing I question - Are the lines being blurred, or are they trying to make certain groups more distinct? I definitely would not put Ultra Beasts in the same mold as, say, the lake guardians or the Swords of Justice, at least not by their appearance and origins from Ultra Space - they're extremely otherworldly, and I guess another point is that they number seven total as of this moment, not including Cosmog, its evolutions and potentially Necrozma.

That being said, I wouldn't be surprised if they later acknowledged both Mewtwo and Type: Null/Silvally in terms of their somewhat similar origins as being the result of an experiment in pursuit of a power for a purpose (Mewtwo being the strongest Pokémon, and Type: Full to combat the Ultra Beasts). And as you said about the island guardians, they definitely fit the existing convention set by previous groups of Legendary Pokémon.

Type:Null / Silvally's status and future treatment remains a big question.

I mean, if they remain legal for use in battle facilities then I see no problem, lol

 

[Ash_Pokemaster]

This point I definitely agree with, except for one thing I question - Are the lines being blurred, or are they trying to make certain groups more distinct? I definitely would not put Ultra Beasts in the same mold as, say, the lake guardians or the Swords of Justice, at least not by their appearance and origins from Ultra Space - they're extremely otherworldly, and I guess another point is that they number seven total as of this moment, not including Cosmog, its evolutions and potentially Necrozma.

The lines are blurred on purpose, as a parallel to other pattern-breaking practices in SM. Terminology changes, but the equivalence of the Guardian deities to Legendary "trios" is not hard to establish, not unlike how the equivalence of Captain Trials to Gym Leaders isn't. Ultra Beasts on the other hand may be an entirely new practice. I guess we must wait and see.

I mean, if they remain legal for use in battle facilities then I see no problem, lol

Only Mythical and Special Pokémon are illegal in battle facilities, and there's no question Silvally doesn't belong in those groups.

 

[Stratelier]

There is also the GTS's use of "special Pokemon" (non-capitalized) which includes Cosmog and Type:Null/Silvally independent of their official status in other contexts.