Alright I'm back with three more Poison takes, and frankly I think two of these I'm going to get yelled at for, but I need to get them off my chest.
Anyway, I'll start with the least controversial one.
C -> B
As of right now, the metagame has a lot of prominent physically attacking Psychic-types that Poison can struggle to handle such as Iron Boulder, Metagross, and most importantly, Gallade. And even ignoring the Psychic-types other big physical attackers that Poison can struggle to handle such as Azumaril, Roaring Moon, Ogerpon-H and Ceruledge run around with Poison have a struggle keeping them off with a lot of teams struggling to fit a hazard setter with both Glimmora and Clodsire seeing only occasional use on Poison thanks to their significant issues on the type and have to resort to no hazards or just relying on Toxic Spikes Toxapex.
Overqwil helps to contain these issues and then some. Being a Physically Bulky Dark-tye it of course handles the Physical Psychic's being immune to their Psychic STAB and taking negliable damage at best (Notably Gallade and Iron Boulder do less than 36% with their other STAB after Intimidate) along with threatening a lot more thanks to its dual STAB Combo, with Crunch serving a solid main stab which also helps against Ghost-types or Barb barrage which it can easily get boosted thanks to Poison being the Poison-type and carrying several mons with stuff like Poison Touch, Toxic Chain or just the Status moves or its own Toxic Spikes. Speaking of Barb of its Hazards, Hatterene can't do shit to it lmao, on all of Poison's other Hazard setters they have to make a choice of choosing between Hatt coming in and pre hard balling to AMuk or going "she won't come in" and facing the consquences if she does, but not Overqwil, Barb Barrage got you covered there, Hazard stack against Fairy and Psychic all you want because they can't stop you. Now it isn't the main Poison Dark of Poison, AMuk's special bulk still has it beat in the Ghost and Psychic matchups and it does have a signifcant flaw of having every Special Attacker making you its bitch (Its special bulk of 65 is garbo) But when it works, it works well.
B -> C
In comparrison to that big write up Clodsire just suffers from being mostly outclassed, AMuk and Glowking are just better special walls covering more matchups better and while yes, they aren't Unaware. Alolan Muk covers a Psychic Immunity and a Ghost resists which are incredible and Glowking packs Regenerator, a Psychic neutraltry and amazing special coverage. Clodsire's biggest claim to fame is that it has an Electric immunity which, yes is good, Poison can struggle into Electric (in my opinion), Electric also has two more things to consider.
A. It is commonly viewed as a bottom 3, usually bottom 1, type and it not worth considering building around for the most part.
B. Zapdos and Rotom-Wash exist, and Clodsire loses to both of them unless it is packing Toxic and they are not packing Sub.
Also its Ground Weak while not offering anyway way to help with our Lando-I or Bloodmoon problem, so scram.
Okay, now the big one.
Awhile back (when this viability ranking started) there was a discussion about S Rank Glue mons that you want to put on a majority of your teams because they are the best option/you having nothing better. And I feel like as of right now, 2/3 of Poison-types in S Rank fit this Criteria.
Alolan Muk, is an amazing special wall, with a resistance to Ghost and Psychic immunity it can easily take on several monsters of this Metagame like Flutter Mane, Hatterene, Deoxy-S, Darkrai and Greninja without breaking a sweat.
Amoonguss, provides breathing room with Spore, Foul play to return power against Physical attackers and Grass STAB to push through Water and Ground like no other mon can in this type.
And then, there is
Toxapex.
S -> A
This comes from a place of love, but I now believe Toxapex no longer deserves to be S Rank with the other two.
The big issues is this, its passive.
Too Passive.
Yes it is a generally good Pokemon with it being able to handle a bunch of stuff in a majority of matchups it runs into, but it runs into the problem of not having enough tools anymore compared to its rapidly growing competiton that has sprung forth to offer solutions to the many problems Poison faces all with Higher offenses and more unique tools than just, Haze and Recover.
Overqwil, as I've outlined prior can create hazards and helps to handle physical attcking Psychic-types or even just slow them down with Intimidate.
Pecharunt, which is even bulkier physically, has setup potetional with Nasty Plot and can pivot with Parting shot.
Galarian Weezing, is both a Ground and Dragon immunity that can spread Burn, along with removing Hazards.
Okidogi, is not a physical wall in the convetional sense, however Bulk up can allow it to become one and allow it to easily steam past Dark, and more important, Steel teams (once the Psychic packing mon is dealt with)
And while I've already mentioned it,
Amoonguss is what you would want to bring into the Water matchup, not Toxapex.
Yes, Toxapex has Regenerator, and is the best Rocky Helmet user of the type, which are great tools but they aren't enough to keep Toxapex high and mighty.