Nobody else is posting so I guess I will. (Some of this post is 
baconbagon's but he was too lazy to post so I'm posting it for him.)
		
		
	
	
 B+ -> A
Rotom-H really isn't A-rank material in a metagame where Rotom-W, Terrakion, and Keldeo are so amazingly prevalent. It's A- at the very most, but it is easily worn down and cant even hit Ground-types with Scald like Rotom-W can.
 S -> A+
Landorus-T still defines the meta to an incredible extent. Every physical attacker has to prepare for it, and defensive Mega Scizor is really rare right now anyway. I view offensive sets to be absolutely incredible as well, especially Explosion sets, which lure in and destroy typical defensive answers.
 A+ -> S
I mean yeah Choice Specs-boosted Water Spout is really strong at maximum health but Scald is strong and useful regardless of Keldeo's health. I agree with this, but Keldeo should become S for its ability to burn all of its foes and not for Choice Specs Water Spout.
 A+ -> A
Serperior's Speed IV doesn't really matter unless it's facing another Serperior, which will most likely be running Hidden Power Fire too. However, it should drop because it's been struggling with a lot of Pokemon.
 A+ -> A
I agree that this should drop. I never really thought of it as A+ material, as it's a passive supporter. Yeah, Moonblast chips Diancie very quickly and Thunder Wave is amazing, but Klefki never had the role to be A+ in the first place. This was a long time coming.
 A -> A-
Terrakion and Keldeo together yes. Chansey isn't really unviable by any means, but the general vulnerability to taunt Thundurus is also annoying, and although Baton Pass / Transform is stupid as usual, it could drop. Not sure though, it's still the fattest thing ever.
 A -> A+
I agree with Mega Diancie being A+. Its frailty and low base Speed pre-Mega Evolving is really annoying, but seriously providing a FakeSpeed resist + Fighting neutrality is a huge utility, and Magic Bounce is great as usual. I don't know about its synergy, I think that Magic Bounce is the utility that puts it up there. It does struggle with Mega Lopunny though just like everything else in the metagame.
 A -> A+
Gyarados cannot be A+ while it's weak to Stealth Rock in a metagame where Thundurus is so prevalent, and it gets worn down so quickly without roost. There's no way is this A+ material.
 A -> A-
Weavile threatens Thundurus and Landorus-T hugely, so I'd prefer A, but I can see it in A- while Shift Gear users and Mega Lopunny are around.
 A- -> B
"gyarados does everything better." Did you forget about Mega Gyarados's Mold Breaker, Dark typing, and the fact that it's more threatening than regular Gyarados at +1 Atk and Spe? Seriously, how does it struggle with Rotom-H at all when Gyarados doesn't seem to?
 A- -> B-
Uh.... Unaware lets it take care of setup sweepers. Immunity to Electric-type moves makes it a good switch-in to Thundurus and Magnezone, something that Gyarados doesn't have. It resists Stealth Rock, and pre-Mega Evolved Gyarados is weak to it. Sure, A- is a bit high but are you kidding me?
 A- -> B+
Yeah it's bad, except the fact that it single-handedly breaks stall with Air Slash, it has Thunder Wave to cripple its switch-ins, it has Oblivion Wing to heal itself up, and its especially effective against Keldeo and Serperior.
 B+ -> B
No, I think it fits in B+. It has the bulk of any other pixie and it has the ability to escape non-Choice Scarf Pursuit with Baton Pass, and it can also use Baton Pass to give teammates boosts, which is enough.
 B- -> B
He's 
The Reptile on forums. B is okay even though Mega Sceptile is really frail in a metagame where fast Ice-types and Ice Shard users are common.
 C -> B
Breloom isn't stupidly strong, and it fails to threaten much of the STABmons metagame, but yes it is unprepared for, and it OHKOes Keldeo and Serperior with +2 Mach Punch. Landorus-T does cripple it though because of Intimidate, but hey what can you do
 (Ganlon Berry Natural Gift). I think this a good change but Breloom still hates FakeSpeed.