Well at least Granbull has something to do in intimidating dragons now. Unfortunately Mawile does what he would do better but with MegaMawile existing Granbull might be able to play with the NU dragons.
Another thing about Gengar and mega evolutions in general, is that it is possible to NOT mega evolve and predict a switch to a ground type. The opponent won't know which of your Pokémon carries a Mega Stone, so it might be an idea to run Gengar without it to lure out opposing ground types (especially if your team has a general weakness to them).
I also think Azumarill will become beastly! It is only weak to Grass, Electric and Poison. Its stabs hit Dragon, Dark, Fighting, Fire, Ground and Rock for super effective damage and it is not resisted by any one type. Ferrothorn resist it, every Poison-Grass Pokémon in existence resist it.
Speaking of which, I think the Poison-Grass typing has become a lot better! Before I often felt that the Poison typing just crippled the Grass, but now it is really of good help! I have noticed in-game how extremely useful Poison stab on my Ivysaur is, and I haven't even gotten to the part of the game with the more threatening fairy types.
Anyway, it is important to remember that even though something looks brilliant on paper, doesn't necessarily mean that it will be good.
I don't know about Azumarill. Dragons resist its priority and its slower than they are so won't be surviving to hit them with Fairy.
90 Base Speed is HARDLY excellent. It's quite terrible in OU, actually. And looking at the thing, I don't see much it can do other than Soundproof Baton Pass that Sylveon can't do better. Maybe a Nasty Plot set, but that's it.What about Mr. Mime.
It's got Nasty Plot, excellent speed, SpA. I think people really underestimate him.
The hackmons meta, is now in terror. I guess more Jolteon's on balloon's.spiritomb now has a weakness
Yesssssssss!! Latias is taking a huge slap to the face with the fairy typesI think that Latias is one of the Pokemon that is affected the most, in a negative way, by the introduction of the Fairy type. The big reason why is because Latias' best set, SubCM, relies solely on Dragon Pulse to deal damage. This was excellent in previous gens because there's not type that's immune to it so it could sweep against pretty much any team, except those with a Steel CMer or something similar. Now, it can't touch teams with a Fairy at all which makes it very unreliable. Everyone knows how bad mono attacking is when the type you're using has an immunity. 2 attacks CM Latias is not as effective and it wants to run something like HP Fire anyway which does jackshit to most Fairies that have high Special Defense. Its offensive sets are still going to be good, but in a lot of situations they are outclassed my Latios.
Good for Kyurem. It might be the most unscathed of the new dragon types, assuming B doesn't get Ice Punch and sent to Ubers this gen.The Kyurem formes got off relatively unscathed by the fairy invasion as well. Normal Kyurem barely ever used its dragon STAB, Kyurem-B might have lost the ability to 2HKO the metagame with CB Outrage (or maybe not, it gets Iron Head) but its superior mixed and Substitute sets are still effective and Kyurem-W still has that absurd special attack and can hold boosting items, unlike megas.
They also got a new excellent partner in Aegislash, who resists everything they're weak to, can deal with Kyurem's best checks such as Scizor and greatly benefits from being paired with a strong special or mixed attacker that can eliminate walls like Skarmory and Hippowdown, something the Kyurem formes are great at.
Hydreigon was OU.
It now has a 4x weakness and something that is immune to one STAB and resists the other. And unlike Steel-types, which it Fire Blasts, it doesn't really have much for Fairies; it might get Sludge Bomb, but otherwise it's resorting to 60 BP Hidden Power Poison or Steel.
Coverage doesn't require a super-effective move, though. Quad fairy type weakness hurts, yeah, especially given Hydreigon's multitude of existing weaknesses, but I don't think it'll bump it down a tier at all. It still has Fire Blast for hitting fairies, it still has good speed and great mixed attacking stats.