After ~300 games, I'd like to make a few VR noms, since the VR obviously needs to be fleshed out a bit. I think that the whole thing needs to be stretched out a bit, but that's a harder problem than just adding to it and shifting a few things.
Additions:
Terrakion: unranked -> A-
+2 Z-Diamond Storm OHKO's almost everything that doesn't resist after rocks, including Tangrowth, Skarmory, Landorus-T, Celesteela, Slowbro, Toxapex, and Mega Venusaur. +2 Mach Punch/Accelerock is also pretty OK at cleaning.
Meloetta: unranked -> B+
Specs 2hko's everything bar Magearna and Mega Scizor. Scarf is a pretty good alternative to PGonZ since it puts pressure on Chansey and can pivot with U-Turn. SpD might be good, but I've never seen it ever.
Yanmega: unranked -> B
It does the same thing it's always done. There are a few new checks to it, but it's still potent if left unchecked.
Sableye-Mega: unranked -> B+
Stall isn't very good, but this definitely has a strong niche there. I've seen a few hard stall teams, and this definitely made life hell for all of my walls/utility pokemon.
Slowbro-Mega: unranked -> B
It's pretty hard to sweep with this thing in a Koko/Grass metagame, but it's still the strongest check to fakespeed in existence.
Skarmory: unranked -> B
While Celesteela has better mixed bulk and offenses, this has more physical bulk, spikes, and SR.
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Umbreon/Mandibuzz: unranked -> B-/C+?
Someone was going on about these, but didn't want to nom them. They pretty much do the same thing: Parting Shot/Foul Play/[recovery]/[hazard clearing]. Umbreon has more support options than Mandi and more overall bulk, but Mandi has more Physical bulk and can use the weakest Beak Blast ever. Z-Parting shot makes them much better than last gen.
Moves:
Thundurus: A+ -> A
Tapu Koko really overshadows this thing
Tangrowth: A -> A+
Regenerator and non-mega give this significant niches over Venusaur. Pure grass also lets it check ground types, like non-SD Diggersby, Zygarde, and Garchomp much more easily. It's also a much safer Koko switchin, since it only takes about 50 from BB, which it can pivot out and heal. AV is pretty good too, but I think the physical set is significantly better.
Heatran: A -> A-
The current metagame and powercreep were pretty unfriendly to Heatran. After playing a few hundred games, I haven't seen it put in nearly as much work as the other A ranked threats. The most potent sets I've seen are Magma Trapper, Z-Solarbeam, and SpD, which both have significant issues. Magma Storm sets struggle to do much in such an offensive metagame, and most switchins that aren't like Chansey can threaten to 2hko it. Z-Solarbeam can't break through things like Zard, Zygarde, Rotom-H, Chansey, SpD Venusaur, Garchomp, and several water types that aren't weak to grass. SpD is destined to get chipped to death in all the games I've seen it in.
Chansey: A- -> A
Chansey's bulk and utility are pretty much unparalleled. It has obvious issues, namely sub, taunt, and chip. But I've seen a significant rise in Whirlwind sets, which punish sub and are potent when paired with spikestack support.
Ursaring: A- -> B
Guts is a fine niche, but it loses to most beak blasters in the first place and is otherwise outclassed by Diggersby.
Tapu Bulu: A- -> B
Pretty much every pokemon that checks this got massively better, and it got spore. Grass is an abysmal offensive typing in this metagame, which is dominated by 4x resists like Celesteela, Mega Venusaur, Zard, and Ferrothorn.
Slowking: A- -> B+
It has way worse typing this gen than it did last gen. The only special attackers that it confidently walls are Magearna, Keldeo, Sylveon, and Heatran. Greninja, Hoopa, Pidgeot, Rotom, and Araquanid give it significant issues.
Toxapex: B+ -> A
It has really, really good typing. It's one of the most reliable pre-mega Charizard switchins, alongside SpD Gyarados. It counters non-LK Lopunny, every Scizor, Araquanid, Celesteela, Sylveon, Buzzwole, Bewear, Keldeo, Tapu Fini, and is a hard check to Greninja, Magearna, Heatran, Mimikyu, TTar, Silvally, and many other pokemon. It's issues are that it's passive, and haze relies on PP stalling, which is prone to getting haxed out.
There are a bunch of pokemon, like Mega Alakazam, Amoonguss, M-Blastoise, Quagsire, Clefable, Diancie, Chandelure, Salamence, Scolipede, Latios, Nido, Torn-T, Volcarona, Zapdos, Jirachi, Jolteon, Kingdra, Weavile, and Manaphy that I couldn't really decide on, but might be worth VR'ing too. I think most of these pokemon could populate the B to C rankings, but I've already nominated a bunch of things, and I'd appreciate someone else's input on these.