Hey everyone, it's been a while so I'm here to give my thoughts on some Pokemon and farm some likes (aiming for 30 in this post, let's make it happen).
A+ to A. Empoleon is probably the most unfitting of the A+ Pokemon. It's a fantastic Defog and SR user, but it's losing some viability with Giavolt Latias and Fighting-type breakers being super popular while birds aren't as good as they used to be.
Stay A. I think other people have said it but Mamo really isn't bothered by Rotom-H unless you are running SR Mamoswine which is a trash set anyway. LO with 4 attacks is a menace to face, and Knock Off with SR up does a clean 75% to Rotom. Even sturdy checks like Alo and Slowbro can find themselves in trouble after taking an early Knock Off and a bit of chip (however Mega Slowbro is broken and will always dominate Mamo). Gligar's rise is also a factor for keeping Mamo A; Hippowdon at least can stomach an Icicle Crash to trade some damage, and Swampert can usually 1v1 it or force it out. Plus Ice Shard is always going to be useful in a tier dominated by M-Aero, Latias, and Hydreigon.
Stay A-. IMO the two sets that are worth using are CB and NP. LO + Slack Off is way too underwhelming and has a hard time finding a turn to heal anyway, so you lose to Scizor at some point. Speaking of which, my biggest gripe with Nape is its inability to check Scizor late game unless you manage to keep it super healthy due to how much +2 BPs do. Outside of that, you need to pair it with some Pursuit user if you wanna use NP, and CB never wants to use Flare Blitz because of the recoil damage eventually putting it in Scizor's range. I think with the amount of support it needs, A- is fitting.
Stay A-. Awesome gluemon, but SR weakness and poor HP stat makes it too easily to overwhelm. It can't switch into stuff like Moltres, Scizor, and Mamoswine as easily as it wants since it can get blown back by Hurricane into SSSS, Bug Bite/Superpower, and Knock Off, respectively. Letting in big bads like Terrakion as well is a huge turnoff. People are already adapting to it as a Defogger, as nobody uses SR Mamoswine anymore (as the Clanger has taken its place as #1 offensive rocker).
A to A-. Bisharp is not as dominant as people thought. It's a fantastic Pokemon on Frosslass HO but those builds are fairly limited in what they look like, and it's hard to justify its usage on other builds. Scizor as a far more useful Steel-type sweeper, and its poor Speed and Special Defense make it a mediocre Latias check. There are simply too many fast Sucker Punch resists, and they are also difficult to wear down due to their resistance to hazards.
B to B+. I am loving Gengar as a breaker against fat and bulky offensive builds. The Sub + 3 attacks set is enough to smash everything while circumventing Pursuit. Despite its poor bulk, it finds a lot of opportunities to use Substitute, as it abuses common Regen cores (Slowbro/Amoonguss), Fairy-types, and slower Fighting-types like Terrakion and Cobalion. I've found the most common immediate switch-in are bulky Ground-types like Hippo/Gligar but they're blown back by Shadow Ball into Ghost-Z.
B to B-. Nowhere near as good as M-Steelix as a defensive Steel-type and OTR sets are walled by most bulky Ground-types. It has super good matchup against offense but can often be stalled out by stuff like Protect with M-Sharpedo and Intimidate. It's a matchup fishing Pokemon and B- reflects that.
to B-. I am loving both these Pokemon right now. Frosslass is hands down the tier's best offensive Spiker with its ability to maintain them against every possible remover with Ghost-typing + fast Taunt + Icy Wind. Zydog's rise goes hand-in-hand with it since it loves Spikes to nab 2HKOs on stuff like Bulky Primarina (unset but people insist on using it), Krookodile, and M-Altaria. Even stuff like Slowbro and Hippowdown get 2HKOd by a surprise Outrage with Spikes + SR up, but you gotta pray for that 2 turn to avoid the revenge kill lol. Zydog is also one of the best immediate punishers of Rotom-H, as unlike Terrakion, it can't Volt out on the switch. That being said, Gligar is a huge nuisance to it since it can't be Toxiced, it avoids Spikes, and it Defogs hazards away so B- is as high as it gets.
B- to C/C-/unranked. What has Snorlax ever done in this tier? Its Terrakion/Scizor bait, Toxic bait unless you run RestTalk but mono-Normal coverage is garbage. I'd say unrank this Pokemon but that might be too drastic for a single drop. For real though, B- is terribly out of place.
B- to C+. Crobat has struggled to find a niche since we lost Serperior and M-Venu. It has an awesome Speed tier and 4x Fighting-type resistance, but its base 10 attack and inability to switch into literally any Fighting-type makes both those traits hard to justify. Grass-types also can beat it with Celebi's Psychic, M-Sceptile's Speed, Rotom-C's Thunderbolt, and Amoonguss just eats a Brave Bird and Spores it lol. I still see it useful to annoy some offensive builds as Flying-type moves are broken, but other than that it's pretty underwhelming.
C+ to unranked. I also have a hard time seeing Cofagrigus' niche in UU. It's simply far too weak, even with a boost, to nab relevant KOs, and it requires 2 turns of setup to get going. There's not much it takes advantage of either outside of choice locked Fighting-types, but does it matter if anything that resists Ghost can take it on?
C to C-/unranked. I don't buy SubToxic as a viable niche for this. Why Toxic a Ground-type when I can just kill it with Grass Knot Zera or Rotom-C? Or have actual defensive utility with Rotom-H or Mega Manectric?
C- to unranked. Bad mon do not use ever, just use Mamoswine.