B-Rank | Top
Malamar is a functional balance breaker that easily pivots into Dragalge/Torterra/Malamar/Magearna and can then proceed to either set up a calm mind (after which it 2HKOes most of the meta) or threaten an analytic-boosted attack into a telegraphed dugtrio switch-in. Z-Celebrate sets are also usable but have low power and only one chance to sweeper, whereas Calm Mind sets can repeatably take advantage of defensive cores and function as a defensive Steel-type when required. However, Malamar is held back by its middling speed-tier and only decent bulk, leaving it forced out by all 3 S-tiers and several other popular picks, such as Purugly.
Magearna has a wide variety of potential sets, but its best set currently is Specs Triage- Having a surefire way to revenge kill Farfetch'd and a generally solid anti-offensive measure is valuable to a lot of teams, and the recovery from Draining Kiss alongside Magearna's great typing and bulk allows it to stick around, usually until the endgame. There are a handful of other sets Magearna can run, namely a Pure Power set that boasts the highest Attack stat in the meta (albeit deceptively low, courtesy of an only 80 BP Steel STAB and no physical Fairy attacks) that can surprise Dugtrio with a powerful Brick Break, and cleric sets with Heal Bell are also viable. However, Magearna's overall low damage output makes it very easy for the opponent to scout the set and then handle it from there- Triage Magearna despises Dugtrio and Dragalge, while Pure Power sets are very easy to offensively overwhelm. Not to mention Ninetales can switch into Magearna virtually for free, only fearing a Volt Switch into a counter.
Rotom-Mow is a decently consistent Shift Gear sweeper, boasting good natural bulk, an ascendant speed tier at +2 with only 156 EVs (outsped only by quick feet Galvantula, which can be outsped with just a few more EVs if that ever becomes common), and good neutral coverage augmented by Steelworker. It finds easy set-up opportunities against common Pokemon like Dugtrio, choice-locked Farfetch'd, and Pupitar. It can also run a subpar but usable defensive Rapid Spin set. However, it isn't extremely powerful at +1, and can often miss KOs that it needs. Also, Stick Farfetch'd deletes it with First Impression, and Fluffy Galvantula can take a hit and immediately OHKO it back with Bug Buzz.
Rotom Wash is not a bad Pokemon by any degree, it boasts great physical bulk, the second-highest special attack in the mod alongside STAB Hydro Pump and the incredibly spammable Shadow Ball, and access to Defog. However, as a defensive defogger Rotom-Wash is almost entirely outclassed by the much more consistent Wailord, and therefore Rotom-Wash is forced into more offensive roles. Scarf outspeeds the unboosted meta and boasts decent power alongside utility options such as Trick, Defog, and Wisp, while also being a functional Farfetch'd and Dugtrio check, but lacks a pivoting move and is therefore rejected in favor of other Scarfers such as Farfetch'd. Waterium/Ghostium Z sets, on the other hand, are powerful offensive defoggers that beat most Stealth Rock setters with ease and generally pressure opposing teams. However, these sets are outsped by most offensive pokemon and very susceptible to chip over time. Note that these Z-sets can also use a pinch berry if your Z is already taken. Basically, Rotom-Wash would be an A Bottom pokemon if Wailord didn't do it better.
Umbreon is a very fat special wall with reliable recovery that beats virtually every special attacker sans Ninetales and Magearna. However, being a special wall that loses to arguably the only truly relevant special attacker is never a good look. It's also very passive when invested fully in bulk even with hitting with a merciless-boosted Hex, relying mainly on Foul Play for damage, further making it Ninetales bait. More offensive sets are possible, but these sets are largely untested and their efficacy remains unknown.
B-Rank | Bottom:
Kyurem has 2 relevant, vastly different sets: Specs and Pressure Stall. Specs is very straightforward set, leveraging Kyurem's great special attack and decent speed tier to fire off STAB Ice Beam and Freeze Dry (which is a great move, btw), alongside Hidden Power Fire to chip Steels and Stone Edge to catch Ninetales. However, it is a pure Ice-type, so it's obviously going to struggle to find switch-in opportunities. Pressure Stall, on the other hand, utilizes Sub/Protect/Noble Roar to slowly PP drain anything that it can take a hit from, use Noble Roar, and then safely Sub on (read: most fat mons). When paired with hazards this set can wear teams down as they attempt to switch around Kyurem to handle it, but it obviously loses to most offensive mons that can threaten it immediately. Kyurem's viability mainly stems from the fact that both sets mandate a vastly different response from the opponent, so Kyurem is most potent before it has taken a move. Regardless, Kyurem is still a middling speed pure Ice-type with little defensive utility, mandating significant team support (both hazards and removal, at least) to get the most out of it.
Ludicolo is a decent defensive water type, but lacks anything that justifies using it for that role compared to Wailord. Therefore, much like Rotom-Wash, it is forced to use more offensive sets in order to find use, which for Ludicolo is its Rain Dance set. With Life Orb and Swift Swim active Ludicolo is a real threat, but there are several problems for this set. The first one is that Ludicolo usually has to take a hit before setting up rain, which when paired with hazards and life orb recoil leaves it with a short lifespam. The other issue is that Drought exists, and while Ludicolo does beat Torterra with Ice Beam, it still leaves it forced to reset Rain and take another hit from Torterra in the time being if it wants to attempt to continue the sweep.
Type:Null is a wallbreaker that, due to lack of super-effective power in both its STAB (which is all it wants to use outside of U-Turn thanks to tinted-lens) and coverage, rarely OHKOes walls and is quite easy to revenge kill as a result. The ubiquity of Ghost-types in the meta just further hurts Type:Null's damage output by forcing to to use the much weaker Iron Head instead of Double Edge/Return. Swords Dance sets can threaten both walls and still scare offense with Bullet Punch, but Type:Null finds few opportunities to set-up with its bulk and typing, and even after a Swords Dance Farfetch'd tanks a Bullet Punch and cleanly OHKOes back. Band boasts more immediate power and an obnoxiously powerful U-Turn, but flounders against offense. This leaves Adamant Scarf as Type:Null's most consistent set, as it can outspeed Dugtrio with a Scarf while still retaining the Adamant power boost. This gives it a much better offense matchup, OHKOing most offensive staples with a round or 2 of rocks damage (or Type:Null's U-Turn). Anything but dedicated physical walls and Ghosts are still 2HKO'd by Double Edge, too. However, Type:Null doesn't fulfill the traditional role of a scarfer, being outspeed by every other scarfer and having a piss-weak Bullet Punch to revenge kill faster threats. Additionally, it's still very difficult to safely bring into play with the low bulk and inconvenient defensive typing.
C Rank:
Crobat, as a physically defensive defogger, sucks. Being immune to hazard damage initially seems appealing for a defogger, but every other aspect of Crobat in this role is terrible. It loses to most relevant phsyical attackers, and those that lose to it simply pivot out into whatever fat Pokemon easy absorbs Crobat's piss-weak Storm Throw. The only hazard setter it actually beats is Torterra by Toxic-stalling it, but if you have to resort to Toxic-stalling to beat the most passive rocker, that's not a good look. It can't even function as a slow pivot, as it no longer has U-Turn. Therefore Crobat is forced to run a "surprise" offensive Life Orb Defog set that leverage's Crobat's passable power with Life Orb, recoil free (but non-STAB) Brave Bird, and Roost to exert some degree of offensive pressure against rockers like Heracross. This set is still pretty weak, courtesy of 70 base attack, and loses to the ground-type rockers if they ever decide to Earthquake. Also loses a lot of the defensive utility Crobat previously had when it was invested in HP. Not a good Pokemon.