Kyurem-B down from A-tier --> B-tier
I agree with this. Though we've all come to the consensus that Kyurem-B is absurdly powerful, all of the factors going against it (e.g. vulnerability to hazards, weakness to priority, average speed tier etc) keep it from really dominating a match. I've given it a shot and rarely did I actually need its brute strength - it was much more beneficial to have speed when it came to overwhelming the opposition.
Approved - Mew definitely still has a niche in this metagame, but a rather limited one despite its huge movepool. The key to making it work is to capitalise on what it can do that something else can't do better - e.g. Lead Mew using Normal Gem Explosion to distinguish itself from Deoxys-D. I think
Azelf should also be added to C-tier, given it has a similar niche as a lead, except it trades bulk for more power and speed.
Victini added to C-tier(?)
This one I disagree with, though I may be slightly biased due to my personal success with Victini. I think its CB set is amazing; double STAB V-create is the "golden arrow" of the OU tier. Even outside of sun, Victini is still a monster and has an impressive movepool in addition. I think its downfalls keep it firmly in
B-tier, though anything lower would be a little harsh, given its potential.
Sharpedo added to B-tier(?)
Agreed, Sharpedo is quite the underrated threat this generation. It does have problems with bulky Steels and the ubiquity of Mach Punch, but it can quite easily clean up in the late-game.
Not really sure about this. I find Ditto is just so inconsistent that it's hard to determine its true viability. Sometimes it can be game-changing, otherwise it is pure dead weight, depending on the opponent's team. I think
C-tier would be more appropriate, given that aspect into account, though I wouldn't lose sleep over it if you decided to go ahead with this.
Aerodactyl added to D-tier(?)
Good move, I have seen Aerodactyl been used on a few successful BW2 teams in the past, but in general it just isn't particularly effective anymore, especially with team preview taken into consideration (though I imagine if Deoxys-D were to be banned, it might have a niche on HO teams again). Oh, if only it learned Head Smash and/or Brave Bird...
Amoongus added to C-tier(?)
Incredibly overhyped at the start of BW2, yet still has a role to play with a good defensive typing, Regenerator and access to Spore.
C-tier seems like the best place for it.
Slowbro added to C-tier(?)
Pretty much only ever used in tandem with Amoongus - on its own, it is a sturdy physical wall but brings little to the table defensive outside of simply tanking hits, and faces strong competition from other bulky Waters, especially Jellicent. It does at least have a decent base 100 SAtk going for it though, meaning it isn't too much of a slouch offensively, and access to Flamethrower/Fire Blast gives it a way past Ferrothorn. I'd say it should be in
C-tier, though it does nearly meet the criteria for B-tier.
Cobalion added to C-tier(?)
I can't really comment on this - I've never used Cobalion on any of my teams, nor have I fought them very often. I've heard it makes for a good offensive pivot with Volt Switch, but given that it hasn't taken the OU metagame by storm,
C-tier is probably the most appropriate for it. I'm really not sure though.
Virizion added to C-tier(?)
Eh, I think Virizion has a little too much competition from Breloom in this metagame. It does have bulk going for it, but it is pretty lacking offensively before setting up. The pace of the metagame may just be too much for it - with Genesect and Tornadus-T waiting in the wings on almost every rain team, it struggles to fulfil its old niche of being a great check to most weather teams. It does still offer an interesting mix of offense and defense though - a good compromise in keeping your offensive momentum whilst still retaining the ability to reliably tank resisted hits. I think this quality is enough is to keep it in
C-tier for now, though I must stress that Virizion is not the Pokémon it once was.