Heya, welcome to my first VR post of the new gen! I've been holding off on this one because most of my ZU related focus was towards ZUPL; however, with my time in the tournament unfortunately coming to a close, it's a good opportunity to revisit the viability rankings before the first DLC drops.
Rises
Stonjourner: S -> S+/ZUBL
This mon is obnoxious; I'll go into more detail in a post in the Stonjourner suspect thread if I make the time for it, but suffice it to say that Scarf, Band, general utility sets, and Rock Polish are all excellent sets that are difficult to predict and can get insane value. By far the best Pokemon in the tier.
Dragonair: A+ -> S
This Pokemon is so unbelievably nuts at sweeping games at the drop of a hat with its dragon dance set. Furthermore, it has quite flexible utility for its moves after the obligatory Dragon Dance; typically it runs some combination of Outrage, Extreme Speed, and a fourth move of choice. As far as what this final move can be, it's pretty flexible - random Tera Blast to sweep unsuspecting teams relying on other coverage, Hydro Pump to clean OHKO Stonjourner and deal massive damage to Sandygast and the like, Iron Head + Tera Steel to setup more easily against SpDef Swalot, Rest to cheese recovery with Shed Skin and continue setting up, the list is nearly endless. Outside of the tera types I've mentioned Tera Normal is the other popular Tera as it further boosts Dragonair's Extreme Speed, allowing it to catch key OHKO's that it typically wouldn't at +1. I simply cannot overstate how many games this Pokemon can win at the drop of a hat off of one bad turn or one misplay.
Vespiquen: A -> A+/S
Vespiquen's insane natural bulk alongside terastalization has given it a powerful place in the tier as a blanket special wall and defensive pivot that can check the likes of Oranguru, Drakloak, Gothitelle, Hypno, and Drizzile, among several others prior to terastalization and can check basically anything else post Terastalization, with Tera Steel, Water, and Dragon being the main popular choices. It also stands out as one of the few walls with access to recovery that doesn't require holding an Eviolite, meaning it can run the Heavy-Duty Boots that define its place in the tier. The many free turns it often gets gives it additional offensive utility through Toxic and setting up multiple layers of Spikes - Spikes which are often difficult to remove due to the tier's lack of reliable hazard removal outside of the rather abusable and overworked Toedscool and the frail Fletchinder. It's also worth noting that its natural base 80 attack, while nothing to write home about, means that even its U-Turn can chip switch-ins like Stonjourner, Raboot, and Crocalor to reasonable success alongside the hazards it so often already has setup.
Crocalor: A- -> A
Crocalor's role as a physical wall was initially in question due to how easily it can be abused by multiple layers of hazards; however, what many players have found is that Croc can succeed
in spite of this hazard weakness due to how absurdly physically bulky it is alongside its Unaware Ability, allowing it to be the only true Dragonair counter in the tier. Its ability to tank powerful physical attacks and inflict status everywhere allows it to pull off hilarious feats like 1v1ing burned Stonjourner while checking many physical attackers like Thwackey, Raboot, Jumpluff, Pawniard, and so on. Terastalization also adds further depth to Crocalor's game, allowing it to remove its Stealth Rock weakness and gain a better defensive typing; Tera Water and Fairy are the main two at the moment.
Pikachu: B -> B+
Pikachu is the strongest special attacker in the tier without choice items, meaning that it keeps flexibility to change moves, and provides a somewhat risky Electric immunity to boot for those feeling brave enough to risk switching into Dedenne's Dazzling Gleam. This makes several variants incredibly threatening, with special attacking and mixed sets both seeing usage throughout ZUPL. The power of Electric STAB alongside Tera Ice or Flying and Surf allows Pikachu to hit everything in the tier for at least neutral damage, often super-effective. Alternatively, it can run a more mixed set, using Fake Out and Quick Attack to pick off weakened targets. It requires more dedication to building around it and isn't as splashable as Dedenne, but absolutely has a place in the tier as the second best Electric Type.
Dewott: B- -> B
Dewott's niche in this tier has expanded with the discovery of special sets to abuse Stonjourner and cocky grasses expecting the physical variant alongside the continued usage of Knock Off, one of the most valuable moves in the tier due to the abundance of Heavy-Duty Boots and Eviolite. Specially-biased Dewott has been seeing quite a bit of usage for its ability to consistently switch into Pokemon like Lumineon, Wugtrio, Fletchinder, Crocalor, and Drizzile, among others. It also helps that it abuses Lumineon and can trade with Drakloak.
Greedent: C+ -> B-
Greedent is surprisingly fat for the tier, making it a noteworthy bulky wallbreaker due to Sitrus Berry allowing it to setup a Swords Dance on almost anything, living almost everything thrown at it, and proceeding to trade at least 1:1 or massively chipping two mons on the opponent's team. I can't emphasize how many times I've thrown a strong move at it expecting it to die and having it live and proceed to setup a Swords Dance in my face, returning to 60-85% HP in the process. It is pretty scared of Knock Off, however, and there are powerful moves that even Greedent can't sustain; Specs Scovillain's Overheat/Leaf Storm kill it after rocks and a layer of spikes while lots of fighting coverage can find OHKOs against it after similar degrees of chip. However, note the asterisk here; after chip. Almost
nothing in this tier can actually OHKO Greedent from full, and the moves that come close can't threaten it for two turns in a row and often can get outplayed by Terastalization.
Slaking: C -> C+
Slaking is woefully underexplored within this tier for obvious reasons; Truant truly is a godawful ability. However, Slaking provides some unique traits as a physical attacker; its excellent speed allows it to outspeed several common Pokemon already considered somewhat fast for the tier like Pachirisu, Lumineon, Murkrow, Fletchinder, and many more. Furthermore, its horrifying base 160 attack stat often boosted further by a Choice Band means that even Stonjourner can't switch into it without risking considerable damage from Earthquake. It also has Throat Chop to hit ghost switch-ins like Gastly, Drakloak, and Banette and Sucker Punch to catch scarfers attempting to outspeed and kill it with powerful neutral buttons or super effective moves. It requires extensive support and cannot be simply slapped onto teams, but when supported well Slaking can thrive.
Drops
Wugtrio: A -> A-
The reintroduction of Lumineon to the tier alongside Drakloak and Calyrex dropping down are all rough news for Wugtrio's signature water-spamming antics, while the rise of Dewott and occasional usage of Mareanie has not been appreciated either, though it can at least hit the latter with coverage. It also gets caught by many Scarf users like Thwackey, Calyrex, Gastly, and Stantler while not being able to run scarf itself due to needing to boost its otherwise somewhat lackluster base 100 attack.
Fletchinder: A- -> B+
Linda hates defensive Water-types and they haven't gone anywhere; if anything, they're more frequent than ever. Gothitelle also seeing occasional usage means that it often can't even safely click Defog into teams including it, as giving Scarf Gothitelle a +2 Special Attack boost can be game losing in the wrong scenario. It also gets abused by Dedenne and Pikachu in addition to the aforementioned Water-types and can only fit one of Brave Bird or Flare Blitz, meaning it either can't pressure Electric-types or can't pressure Dragon-types, neither of which is good - it also gets thoroughly abused by special variants of Swalot who don't mind trading a burn for tons of damage on Fletchinder or chasing it out, and psychics in general can use Fletchinder as setup fodder as well.
Flareon: B+ -> B-
Flareon is another fire type that hates waters, and it finds itself in more and more problematic situations by the day. Defensive sets often have a proclivity for passivity unless they run the recoil-inflicting Flare Blitz, which cuts into its role as a defensive Pokemon, while offensive sets typically aren't good since they often run out of steam before they get the job done due to Toxic's continuous ticking and Flare Blitz and/or Double Edge's recoil. It also isn't good that offensive Flareon doesn't do much damage to Water-types without Trailblaze, which isn't even all that powerful, and finds itself stonewalled by Stonjourner.
Bramblin: C -> C-/UR
This Pokemon is just a straight downgrade from Toedscool outside of being able to spinblock as a defensive Pokemon, something that often gets abused by Banette, and is horribly outclassed by Drakloak offensively; not to mention Vespiquen and Quilladin are also better spikers. The role compression just isn't worth it for a Pokemon that's ridiculously abusable by most of the tier. Just use one of these other mons instead.
New Additions
Calyrex: New -> A-/B+
Calyrex finds itself as our newest grass with okay bulk and either a scary double dance set supported further by Tera or a choiced set with STABs, Pollen Puff/Tera Blast, and Trick. Time will tell if it stays solid, but for the moment it's a decent new addition - as long as it avoids U-Turn, anyway.
Drakloak: New -> A+
Drakloak is an excellent new addition to the tier as a pivot and spreader of status. Infiltrator to work around Substitute sets is also invaluable, and its bulk isn't the worst when supported by Eviolite and some HP investment. It has three main sets at the moment; offensive pivot with U-Turn/Draco Meteor/Hex and its choice of TWave/Will-O, full offensive with Will-O/TWave/Draco/Hex, or bulky support with some combination of Dragon Tail, Night Shade, RestTalk, TWave, Will-O, and U-Turn, all of which have found success in their own way. Drakloak certainly isn't going away soon, at least not until Home happens.
Lumineon: New -> A
Lumineon's back and better than ever. An excellent specially defensive pivot that checks waters and can occasionally even go offensive with Scarf/Specs, Lumineon is great at facilitating its teammates while being annoying in its own right.
Ampharos
Calyrex
Camerupt
Carkol
Drakloak
Dunsparce
Glimmet
Lumineon
Luxray
Rotom-Fan
Stonjourner
Banette
Dedenne
Dragonair
Oranguru
Gothitelle
Raboot
Sandygast
Toedscool
Vespiquen
Wugtrio
Crocalor
Fletchinder
Grimer-Alola
Hypno
Jumpluff
Mareanie
Murkrow
Scovillain
Drizzile
Flareon
Pawniard
Pupitar
Quilladin
Stantler
Glalie
Hippopotas
Pikachu
Pincurchin
Sneasel
Sudowoodo
Dewott
Eiscue
Gastly
Krokorok
Morgrem
Mudbray
Pachirisu
Seviper
Tinkatink
Tropius
Bramblin
Greedent
Kricketune
Persian
Zweilous
Charmeleon
Delibird
Eelektrik
Foongus
Greavard
Gumshoos
Kubfu
Shroodle
Slaking
Wooper-Paldea
NEW -> S/BAN Unlike Drizzile, an underrated Pokemon in its own right, Frogadier’s higher Speed outspeeds targets like Raboot and Murkrow, two popular wallbreakers. Perhaps the biggest selling point is Spikes, as it adapts very well since most Spikers are either weak to Ice Beam (Quilladin, Toedscool, Bramblin, Vespiquen), lack defensive utility and are frail (Glalie), or is largely uncommon at this point (Pincurchin). While certain walls like Mareanie and Specially Defensive Oranguru can evade the 2HKO after Stealth Rock against Choice Specs sets, they can be pivoted on with U-turn (like Drizzile), they’re vulnerable to be either hit with a layer of Spikes, making them less reliable later on as switch-ins, in conjunction with Rocks (unlike Drizzile), or they can be ruined by Switcheroo (also unlike Drizzile). Compared to Vespiquen and Quilladin, Frogadier is significantly more dangerous immediately, as it’s got good offensive presence courtesy of its strong STABs, Protean Ice Beam, pivoting, and is much faster than them. 
:
C -> UR, nobody uses this. It had a sort of niche when Acid Armor Swalot was the meta defining threat and Dunsparce was spaming recklessly Body Slam. But now, I really don't the appeal of using such a weak and frail Pokemon.
B -> UR, no reason to use it over Dragonair.
or 
. usually is able to drop at least 1 mon in a game and can come in on plenty of the tier's walls. Basically trades 1 for 1 while easing up pressure on your team's bulkier mons, a niche which is pretty helpful in the spikestack infested meta.
