Scizor has greatly appreciated the ban of Melmetal, allowing Scizor to reign as the best steel type in the meta once again. No longer is there a Melmetal to punish Bullet Punch locked Choice Band Scizors, or paraflinch bulky sets into oblivion, or take any one hit bar +2 LO Superpower and cripple it with Thunder Wave, significantly freeing up Scizor's set diversity. Bulky Scizor running Knock Off acts as a fantastic answer to SubTox Aegislash, being able to boost past King's Shield's attack drop and Roost off anything but a SpDef drop from Shadow Ball, among many other threats such as any non Meteor Beam Nihilego, Zeraora (if you don't mind losing your item), non-Fire move Mega Altaria, and more. Choice Band is now also a much more deadly form of speed control, capable of revenge killing most sweepers with minimal chip damage, get offensive Pokemon in with U-turn, cripple Celesteela with Knock Off, and generally be a menace. LO SD is also still a dangerous sweeper, though it has become slightly less useful with the fall off of Screens thanks to the Light Clay ban. Its large set diversity and the effectiveness of each of these sets has merited its rise to S-.
Amoonguss is without question the best defensive Pokemon in the meta right now, often feeling unkillable in most games and additionally carrying the threat of Spore and Sludge Bomb poisons, making it threatening enough to allow it to fit on Bulky Offense teams, a feat not many defensive Pokemon can claim and preventing it from becoming a momentum sink. It checks a plethora of top tier Pokemon, such as Mega Altaria, Urshifu-Rapid-Strike, Zeraora, Primarina and Mienshao, and the list of Pokemon that reliably break it is short. The bans of Melmetal and Alakazam, both Pokemon who significantly threatened Amoonguss, has done nothing but benefit it. Its presence and influence is unquestionable, and a rise to S- was deemed appropriate.
Nihilego was already easily one of the most threatening Pokemon in the meta, and Melmetal's ban has served only to increase that threat. The Rocks Three Attacks set is the most effective Stealth Rock user in the meta right now while also checking meta threats like both Moltres and Defog Salamence, while the Meteor Beam sweeper is still extremely dangerous to face. Without question a top threat right now, and it has risen to reflect this.
Salamence is one of the most splashable Pokemon around right now, being able to check Urshifu-Rapid-Strike, threaten Amoonguss, check Mienshao, and be an acceptable Defogger. Generally just it doing what it has been doing but better now that there's no Melmetal to threaten to abuse it for a cheeky kill.
Without question, Mienshao is the best (and arguably only genuinely good) Choice Scarf Pokemon around right now thanks to its speed tier, decently powerful STAB, coverage and Knock Off. Regenerator makes it feel borderline unkillable and can often threaten to clean lategame with its Close Combat or cripple checks with Knock Off. Additionally, its Life Orb wallbreaker set uses its seeming unkillability to repeatedly threaten to punch holes in walls and negate the downside of Life Orb or attempts to weaken it with Rocky Helmet, cripple checks with Knock Off, and U-turn on the few Pokemon that don't mind it into another Pokemon.
Light Clay's ban has done surprisingly little to keep Moltres-Galar from being a top threat. While it still remains to be seen if it is still broken without the possibility of hiding behind screens and tanking every hit and then some, it is regardless still a dangerous sweeper and wallbreaker. Aegislash becoming one of the top Pokemon in the meta has also benefitted it greatly, as it abuses and threatens virtually every set. RestTalk is also still more than usable, utilising its ability to repeatedly trigger Berserk to turn into a dangerous balance breaker, while shutting out Aegislash even harder.
Rhyperior is arguably the best bulky non passive rocker in the meta right now, being able to check almost every Defog user bar Rotom-Wash, as well as break several slow defensive cores with Swords Dance and its dual STAB.
With Amoonguss being as dominant as it is, Mega Manectric's ability to weaken it significantly with Overheat is quite valuable to many teams. Zeraora is incapable of doing much more than mildly inconvenience Amoonguss without giving up its Volt Switch and Knock Off spamming offensive utility and longevity, making Mega Manectric much more worth considering now as, while it cannot cripple things like Zeraora, it instead has a respectable damage output. It of course still maintains its dislike of Stealth Rock, however, preventing it from rising any further, and in any non Amoonguss matchup Zeraora is still generally much better.
With the vastly improved teambuilder breathing room, and generally much bulkier and slower metagame created by the ban of Melmetal and Alakazam, teams can teams account for its lack of defensive utility without breaking its back, and it is no longer as easily pressured by faster Pokemon due to the speed tiers being generally lower now, Terrakion has begun to thrive as a terrifying wallbreaker that defines one of the most important speed tiers of the meta right now. However, its flaws, namely lack of defensive utility meaning it demands a significant amount of support, meaning that it must usually be built around rather than just slapped on any old team like other wallbreakers, and prevalence of Scizor's Bullet Punch, keep it from A+.
Roserade continues to prove itself the single best Spikes mon in the meta right now, compressing several roles like Urshifu-Rapid-Strike and Mega Altaria check while not being passive like Skarmory. Generally this rise is a continuation from the previous one, so there isn't much else to say.
Nidoking is a dangerous offensive rocks setter that no Defog user even wants to attempt to switch into, additionally doubling as a threatening wallbreaker capable of turning balance cores into mush. It also deters Choice Band Terrakion from clicking its STABs, as Nidoking can easily exploit a Choiced Terrakion for a free kill, and is a very effective Nihilego check, making it an answer to two very threatening Pokemon. That said, it still needs prediction to truly shine, keeping it from going any higher, and offers little defensive utility. It's also a somewhat sketchy volt immune as it doesn't like losing Life Orb to Zeraora and has no recovery.
Azelf is an effective form of speed control and potential win condition that benefits from Terrakion being a dominant threat that must be checked offensively. The general set you'll see is a Heavy-Duty Boots Knock Off + U-turn pivot in a similar vein to Zeraora. It is effective at compressing roles for teams, as it also packs a ground immune and a resistance to Mienshao's CC, making a lategame CC cleanup harder to pull off.
Cobalion has a valuable niche in compressing a Nihilego, Scizor and Zarude check, a rocker and a pivot in one slot. A more offensive SD set can also sometimes put in work with Stone Edge over Volt Switch.
Nidoqueen is the bulkier alternative to Nidoking that can also be a passable Toxic Spikes user, and is also a more reliable check to Nihilego and Choice Band Terrakion. It's not as powerful as Nidoking, however, as it never runs Life Orb.
Melmetal no longer exists to give it huge competition, and it additionally checks Nihilego and Zeraora, being a solid volt immune. However, it is still a mega that isn't Mega Altaria, and Mega Aggron is generally superior.
Zygarde-10% appreciates Tangrowth generally falling off in favour of Amoonguss, who does not resist Thousand Arrows. The existing steels now also do not threaten to turn it into a free kill like Melmetal did, and Gligar falling off is quite good for it too.
Starmie is an effective form of speed control that also spins on a lot of rockers, being akin to a Levitate-less, Knock-less and U-turnless Azelf. Its typing also lets it punish Choice locked Urshifu-Rapid-Strike and check Scizor mid sweep. Analytic also lets it hit reasonably hard against the Pokemon it forces in, keeping it from being passive.
We banned Blaziken a while ago so Infernape is no longer hideously outclassed. It's still lackluster and generally outclassed by Terrakion as a Swords Dancer, and Nasty Plot generally really needs the boost to be effective, not to mention it's also checked by Nihilego, Moltres and Mega Altaria anyways. Mixed sets are generally too weak. Thus, it will not be returning to its previous rank.
Melmetal was an enormous threat to any Scolipede sweep, threatening to vaporise it with Double Iron Bash and eating any hit Scolipede could throw at it with ease. Now, with Melmetal gone, Skarmory at a low, and a slight decline in Bulky Scizor (if mostly because it has more options now), Scolipede is actually capable of being effective now.
Sharpedo-Mega greatly appreciates the teambuilder freedom letting it fit on Spike stack BO and Balance much more easily, no longer confining it to HO. With correct play with pre-mega Sharpedo (ie. killing something weakened as base then protecting), you can reach +2 speed and outspeed Scarf Mienshao and kill it, something that's neat in the current meta.
With no Melmetal to completely outclass it in every way except Stealth Rock, Mega Aggron is once again a respectable SpDef steel that checks several important special threats and sets rocks. In addition, it isn't particularly passive either, but its lack of recovery holds it back significantly, much like with Mega Steelix.
Melmetal being banned lifts an enormous roadblock for Staraptor, as not only did Melmetal make Staraptor a liability, it also restricted teambuilding to the point where it was extremely difficult to make an effective team with it, let alone justify running it due to the prevalence of other strong wallbreakers. Staraptor is once again freed from BL Hell.
Klefki is a somewhat irritating to deal with spiker and utility Pokemon, crippling sweepers with Prankster Thunder Wave and checking Moltres-Galar and Nihilego.
Diance is a bulky rocker that checks Moltres and Moltres-Galar more reliably than Nihilego, while also being able to switch into Salamence with much less fear of Earthquake than Nihilego.
Crobat is a decent speed control/pivot that checks Mega Altaria, Amoonguss (once Spore is used), and Mienshao. It's an awful Defogger though, so don't bother.
While it's speed control that can't check Terrakion, its real strength lies in being able to completely abuse Amoonguss post-Spore to Toxic just about everything and its nearly unresisted STABs, as well as being able to spread Knock Offs. It checks a lot of things that aren't Terrakion too, so if you just pack a second speed control Pokemon you'll generally be fine anyways.
Similar to Terrakion, but much more extreme, Melmetal's ban has freed up teambuilding to the point where it's actually possible to build a team with Conkeldurr. While still generally outclassed by Urshifu-Rapid-Strike, Terrakion and Buzzwole (among many other fighting types), its Guts boosted Facade lets it break Amoonguss and Mega Altaria much more easily (ie. without predicting with coverage it just Regens off anyways or using a Z-Move), while still being an obscenely strong wallbreaker, giving it a solid enough niche it merits ranking. Mach Punch is also slightly more valuable now, nailing Terrakion and weakened Nihilego. However, it is important to remember it still suffers from several issues - while its stats imply it is bulky, its typing leaves it with no defensive utility to speak of, and its low speed and exactly negative passive recovery exaggerates this issue even more - while it's possible to build with it, it is still very difficult. It can't even really run Drain Punch as it needs Close Combat, Facade, Mach Punch and Knock Off (Knock Off being for bulky psychic types and Aegislash). Regardless, it can be a terrifying wallbreaker in the right matchup.
Barraskewda is a respectable offensive speed control Pokemon that can check Terrakion and notably outspeeds Mega Manectric, making it dangerous for BO teams running it for Amoongus to face.
Mega Pidgeot is a solid form of speed control with a powerful hurricane and high speed stat, with a heat wave just strong enough to bother the meta's non-Celesteela steel types. Additionally, its Roost + Refresh (with Hurricane and Heat Wave) set is decent pivot to Aegislash with Stealth Rocks removed, but it must be careful of Close Combats as it roosts, though it can just about eat one and retaliate against the now much frailer Aegislash with a Heat Wave. That said, its rocks weakness, usage of the mega slot, and general competition faced from Tornadus keeps it from moving any further up.
Sneasel is a respectable offensive Pursuit trapper with offensive presence that can spread fairly strong Knock Offs and deters common Knock Off absorbers with its Ice STAB.
Mega Sceptile is respectable speed control option that completely exploits Rotom-Wash and to a lesser extent Zeraora, and can reliably revenge kill Terrakion. It still faces many issues, namely Celesteela, Amoonguss and Mega Altaria still being dominant, but other dominant steel types such as Scizor and Aegislash are either weak to Hidden Power Fire or quick to be worn down.
Umbreon is an acceptable Wish passer on Mega Aggron/Mega Steelix balance teams that also need a decent check to Moltres-Galar and Aegislash. It still remains very passive, however, so you definitely shouldn't slap this on any old team, and it does lose to Aegislash if it gets Close Combat-ed on the switchin with rocks up so don't bank on this being your only answer.