Mega Blastoise: A+ -> S
Mega Blastoise has solidified itself as easily the most threatening special attacker in the tier (bar like ninetales which is stupidly good too). The sheer amount of power this mon packs is insane and the great coverage it gets makes it stupidly hard to wall unless you're using Milotic/Florges/Pyukumuku, all of which are easily abused by some common Pokemon like Toxicroak. Rapid Spin makes it the best type hazard control available and 4 Atks, although rare, is one of the most fierce wallbreakers in the tier. The recent standardization of bulky Mega Blastoise (which is much better than Timid btw) adds to its serviceable defensive utility by making it an actual Entei check (if running 168 HP) or hitting far harder with a Modest nature (especially if running max Special Attack). Its low speed hurts it, but its solid bulk mitigates this issue by a lot, and you still outspeed lots of common walls like Cresselia anyways. Even though it dislikes bulky Water-types rising because of Entei, it is still such an influential Pokemon that I'd rank it above all of the current S Ranks atm.
Entei: A+ -> S
sacred fire is unhealthy its got like 2 counters espeed is too much blah blah honestly everyone's already said just about everything that needs to be said about entei. I don't think it would be helpful to regurgitate everyone's statements again.
Bronzong: A -> A-
While Bronzong is just as defensively potent as always, the meta has managed to adapt to it to a large extent. Pokemon that can easily beat it, like Mega Blastoise, Entei, Ninetales, Zygarde-10%, and Roserade are on the rise, and Pursuit is still one of the best moves in the meta, in part because of Bronzong's popularity itself. Drapion, Sneasel, Escavalier, and Doublade are all menaces in the tier, all of which are able to trap and eliminate Bronzong if they get a free switch-in. This can be extremely problematic for teams that rely on Bronzong as their sole Fairy/Ice/Ground/Psychic check, since powerful wallbreakers like Gardevoir, Vanilluxe, Nidoqueen, Meloetta, and Comfey can rampage through teams without it to stop them on their tracks. Although it has great utility options (Stealth Rock / Gyro Ball / Psyshock / Psychic / Toxic / Protect / Psywave), it is forced to choose only four of them, making it more vulnerable to certain checks depending on what it runs.
Noivern: A > A-
I would like to start off by saying Noivern is definitely a fantastic wallbreaker and a threat most teams need to prepare for: being able to run several variations of sets like Taunt + Roost, Stallbreaker, 3 Attacks, max hp and Choice Specs. Its great typing makes it a pretty splashable and defining pokemon in RU, earning its spot on some balanced and bulky offense teams, and an amazing speed stat let it revenge kill numerous threats like Virizion and Salazzle. However, I feel it was really overhyped initially; it just does not hold up with the rest of the A-ranked pokemon. Checks to Noivern are at their prime right now. Rock-types are in demand because of the prevalence of Entei and Fairy-types are as good as ever, and giving free turns to very threatening sweepers like Barbaracle, Comfey, and Tyrantrum is really bad. Other counters like Registeel, Ampharos, and Slowking are rapidly becoming more and more relevant in the meta. Noivern, while still really good, just struggles to keep up with the higher ranks.
Feraligatr: A- -> B+/B
The problem with using Feraligatr, in my opinion, is that you are missing out on using another of our fantastic water-types; offensively Barbaracle, Golisopod, Mega Blastoise, and hell, even Bruxish are all extremely threatening and most importantly, offer excellent defensive utility while still pressuring the opponent. While Swords Dance Feraligatr is really hard to wall, its complete lack of defensive utility, even despite its decent bulk, 4 moveslot syndrome (it wants Swords Dance / Liquidation / Aqua Jet / Superpower / Ice Punch / Crunch), and middling speed stat just makes it harder to justify using right now. Dragon Dance was extremely potent in SM, but it has fallen off really hard lately. More and more checks seem to be resurfacing and its low speed for a sweeper means almost every relevant Choice Scarf user outspeeds it even at +1 (bar Tyrantrum). The prevalence of bulky Water-types to check Entei is also a huge thorn in Feraligatr's side. The meta has completely adapted to the threat of Feraligatr and that deserves a drop from the A ranks.
Flygon: A- -> B/B-
I don’t think people were really taking Dragon Dance Flygon into account when it dropped last shift. Instead, the mediocrity of the Choice Scarf set was pointed out and it was the reason for its drop. However, around the same time, people were starting to realize the potency of Dragon Dance Zygarde-10%, which, compared to Flygon, requires significantly less support from its teammates to pull off a sweep. Despite both Dragons having the same attack stat, Zygarde-10% has several other advantages that make it worth using over Flygon most of the time. Firstly, having a 115 base speed stat compared to Flygon’s 100 is easily the most significant difference. It allows Zygarde-10% to comfortably run an Adamant nature and still outspeed 100 base speed Choice Scarf users, which makes a big difference compared to Flygon being forced to run a Jolly nature or risk being outpaced by 90 or 100 base speed Scarfers. Adamant Flygon is an option but you miss out on a lot of relevant speed benchmarks, which is why I'm really not a fan of it. Secondly, Zygarde-10%’s access to Thousand Arrows makes it far less dependent on team support to sweep teams. For example, it allows it to beat really common defensive and offensive pokemon that Flygon struggles with; Bronzong, Moltres, Gardevoir, and Rotom-Heat all drop to Thousand Arrows, but can avoid Earthquake and either revenge Flygon or force it to lock into Outrage, which is far more exploitable given the prevalence of Fairy- and Steel-types. Finally, Zygarde-10% has Extreme Speed, which lets it revenge kill the few Choice Scarf users that can outspeed it, like Salazzle, Delphox, and Espeon. It's also pretty helpful when unboosted. Although Flygon's better bulk + Levitate can definitely come in handy, Flygon lesser Speed, the necessity of higher team support, and being forced to waste its Z-Move whenever it finds a Ground resistance, makes it a far less appealing option. A Pokemon so thoroughly outclassed like Flygon should definitely not be so high up the viability rankings.
Barbaracle: B+ -> A-/A
Barbaracle is just fantastic right now. Shell Smash makes it one of the most threatening Pokemon in the tier, even more so than some of the pokes in the A ranks. Its great typing gives it a lot of setup opportunities versus some of the best mons in the meta, and can force choice locked pokemon to be extremely careful when using their coverage lest they give this monster a chance to click Shell Smash. The aforementioned typing gives it excellent resistances to some of the best offensive types in RU, particularly Fire, Flying, and Normal. Lets briefly go through some of the more relevant Pokemon it can set up against: Fire STAB locked Ninetales, Salazzle, non-Draco Meteor Noivern, Snorlax, Moltres, and Glalie. Because its typing is also offensively great, it gives it basically a free moveslot in which it is free to run one of Aerial Ace / Substitute / Protect / Low Kick / Return / Taunt. Some of those are admittedly pretty niche, but they are a testament to the versatility of this mon. While its speed isn't actually that great unboosted, once it gets off a Shell Smash very few Choice Scarf users would be able to revenge kill it, (pretty much only Salazzle and Espeon) something that very few offensive pokemon can boast. Being able to blow apart most defensive answers like Milotic or Bewear with an insanely powerful +2 Continental Crush is an excellent way to pave a sweep from another Pokemon like Entei, which is why it tends to find itself in numerous offensive and balanced teams alike.
Toxicroak: B+ -> A-
Toxicroak is really enjoying the state of the metagame right now. Entei being everywhere means an increase in bulky Water-type usage, which it really really likes cause it means free Sword Dances for it. It also fares well against some of the tiers best offensive Pokemon like Mega Blastoise, Virizion, Golisopod, and Barbaracle. Although it does suffer from pretty bad 4mss, this also means the opponent is left in the dark against an opposing Toxicroak because you never know what to expect from it. Additionally, the emergence of the Choice Scarf set is another testament to its versatility. Despite a not so great 85 Speed stat, it still outspeeds a large portion of relevant Pokemon, like non-Choice Scarf Gardevoir, Mega Blastoise, and Tyrantrum, and it can run Sucker Punch to have an even better matchup versus offensive teams. It can run a variety of items like Life Orb, Poisonium Z, Choice Scarf, and Darkinium Z, letting it choose its checks and counters. This makes it quite a flexible yet powerful mon and in my opinion, this warrants a rise into the A ranks.
Swellow: B -> B-/C+
Swellow is actually a pretty neat Pokemon; Boomburst + U-turn makes it a real pain vs offensive teams, especially after considering the rarity of offensive Steel-types, and its Speed tier is so useful versus threats like Salazzle, Virizion, and Noivern. However, it has a number of flaws that I feel like have been ignored for a long time. Ever since its prime in SM, it just hasn't been as consistently effective in my opinion, especially considering how the meta has evolved to favour more balancey/bulky offensive teams. While offense and hyper offense are still viable, the other two are simply more consistent and common. This means the types of team structures Swellow is best at breaking apart aren't used as much anymore. Considering Rock-type Pokemon like Barbaracle, Rhyperior, Omastar, Tyrantrum, and even Gigalith are at their heyday and there's usually at least one of these on every team, Swellow has a hard time fitting onto a team due to the amounts of support it needs to succeed, and its complete lack of defensive presence which means you're essentially playing a 6v5 defensively. It's still a decent mon overall but it has too many flaws that prevent it from being consistently useful imo.
some other noms i agree with
Sneasel: C- -> C+
Omastar: UR -> C
Scrafty: UR -> C/C+
Sun duo: B -> B-/C+
Uxie: C -> higher
