Like the title suggests I have a theory on eevee. The first 3 eeveelutions were fire,eletric, and water right? And what were the mascots elements for the first three games? the same thing.
Articuno is Ice, not Water. Not much of a difference, but still.
Not to mention the birds weren't actually mascots of Gen I. The mascots of Gen I were the final evolutions of the starters (Blastoise, Charizard, and Venusaur, judging by the box arts), plus Pikachu. If that's what you
meant, then you'll have to take into consideration the fact that the original two mascots for Gen I were Charizard and Venusaur (Japanese Red and Green) -- or Fire and
Grass. Blastoise was added later (in October 1996 for the Japanese, as opposed to February 1996 for Red and Green), as was Pikachu (September 1998 for Japan). So, the Eeveelutions came
way before Game Freak decided to set out planning Yellow, and even then, the original set would have included a Grass Eeveelution to match the mascot for Pokemon Green. (That is, Leafeon would have appeared much earlier if this logic applied. Likewise, Glaceon would have appeared instead of Vaporeon if the Eeveelutions' types were meant to match the legendary birds.)
1. The three mascots elements were fire/water/flying.
Groudon is Ground, not Fire. Any drought-related attributes (including its own ability) relate to the concept of parching the earth to create dry land or are meant to counter Kyogre's abilities as an oceanic Pokemon.
2. Hoenn pokemon really felt different and out of place.
So did Sinnoh Pokemon, according to a number of people. Really, the reason why each gen's Pokemon feel different is because they're successively newer, so the designers try to experiment. That's how you got a dancing pineapple (Ludicolo) in RSE and a Power Rangers monster-of-the-day (Drapion) in DP.
3. No really new features (besides graphics and some other crap)
Erm...
1. Two bicycles, introducing the element of changing speeds and areas accessible only by certain means (without the use of HMs).
2. Running shoes.
3. Television.
4. Contests.
5. Berry farming.
6. Natures.
7. Abilities.
8. Pokeblocks.
9. Attributes (beauty, smartness, et cetera).
10. Actual double battles.
11. Diving.
12. Battle Frontier (in Emerald).
13. Secret Bases.
14. Trainer's Eye.
15. New features in the Pokedex (namely, size ratio).
16. Weather outside of battles.
17. Icons that are actually of the Pokemon's species, as opposed to breeding group (a la GSC) to make it easier to organize your team.
18. Better formatted Pokemon storage system to allow easier organization. (It also files your Pokemon into new boxes, rather than requiring you to change boxes every time one fills up, unlike in RBY and GSC.)
19. New evolution methods (beauty for Feebas, empty space in your party for Shedinja).
20. New capture methods (Feebas).
21. Damage/status induction by touch (with Rough Skin, Static, Poison Point, et cetera), which started to reestablish what it meant to be a physical or distance move.
So, yes, there were new features in RSE. I mean, okay, some of those aren't particularly vital (although the metagame just isn't the same because of the introduction of natures and abilities), but a number of them are useful and still new.
Leafeon- Shows the eternity of nature.
Nature isn't entirely eternal, though. It changes constantly.
Rock cause wtf my eevees a stone?!
WTF my Eevee's a puddle of water?!
Seriously, there's been weirder ideas out there. Vaporeon, for example, possesses the ability to
melt in water.
Flying cause we cant have a griffin as a regular pokemon we need one as a legendary.
Why? It's not like we've never had legendary creatures be regular Pokemon. Espeon, for example, is based on a legendary two-tailed cat demon of Japanese folklore. Griffins would actually probably be less interesting compared to the bakeneko, considering the fact that all a griffin is is an eagle with a lion's rear.
Not to mention it's not like Pokemon never had medieval beasts as non-legendaries anyway. For example, the dragon (often associated with griffins) comes up now and then with such Pokemon as Charizard. Unicorns, for another example, have their own representation in Rapidash.
Overall, while you start to introduce an interesting theory (that the Eeveelutions may have something to do with the legendaries of a region), I'll have to agree that there's definitely some gaps in your reasoning (particularly when you go on to talk about other Eevee types... and, well, don't go into further detail about your opinions, which left things like calling Groudon a Fire-type and the legendary trio the mascots of Gen I when none of them were sort of hanging, like you were
going to say something there but just didn't).
Personally, I believe that the reason why there's no new Eeveelution in RSE is because there's no
Eevee in RSE. You need to trade in order to get one in the game. Now, this argument
could circle back to the argument that, "They would have included Eevee if they were planning a new set of Eeveelutions," but my guess there is that, after creating five Eeveelutions, they probably opted for a break. Not to mention the fact that the gen seems to focus more on new Pokemon, rather than bringing back old ones. (About 30 families reappeared in Gen III, as opposed to almost 40 in Gen IV, and not all of the latter had new additions to their evolution lines. And even then, many of the Pokemon that reappear in Gen III are found
only in the Safari Zone, a place practically reserved for older gen Pokemon, or are otherwise rare anyway. The rest of the region is filled with mostly new Pokemon.)