Hello. I wanna give my take based on numerous discord conversations, what I have personally seen and just for interest in the tier.
Having watched BKC:s video with Peng, I do think it outlines the tier pretty well right now and what is even on the table. It very clearly shows that we have 3/4 real bans to keep the status quo, after that we are breaking the fundamentals. I am of the stance that the current tier we have is very good as a base, and we should focus on keeping the tier largely as is instead of going for a true game changers.
I think there are only 3 mons that are even on the table, even if the tier discussion post says otherwise. These mons are Cloyster, Reuniclus and Thundurus-Therian, in that order. Anything else feels way too out of reach for the current moment, stuff like Latios and Excadrill are a waste of time even discussing when without at least a big tour without one, there is not a large enough push to ban either of these mons. I also do think banning 2 of the mentioned list earlier will already lessen the brutality of Latios and Excadrill, which I am going to explain below.
Let's start with the mon that is probably going soon already and isn't changing the tier largely: Cloyster. Cloyster represents cheese in the BW OU tier. It is the ''mu shell'', sometimes it does a lot and sometimes it's useless. When the original suspect was done, Cloyster was mainly a physically oriented mon, but with the discovery of Mixed cloyster, it lost one of it's biggest true counter play measures, as you can't reliably counter the thing with something like a Jellicent anymore. Even the mighty Keldeo is prone to dying to Cloyster after it's chipped
+2 252+ SpA Expert Belt Cloyster Hidden Power Grass vs. 0 HP / 4 SpD Keldeo: 326-386 (100.9 - 119.5%) -- guaranteed OHKO
So yeah, cheese is bad in a game of competitive pokemon and Cloyster should go outright for these reasons.
(Just wanna post this here for shits and giggles
+2 252+ SpA Cloyster Surf vs. 252 HP / 0 SpD Reuniclus in Rain: 415-490 (97.8 - 115.5%) -- 87.5% chance to OHKO)
Then, let's start with the actually broken one: Reuniclus. Reuniclus is historically infamous for being dependant on it's environment. It becomes way less used at times, only to come back again next year in SPL when the meta favors it, becoming an absolute demon once more. Reuniclus issue is it abusing every single factor about BW OU perfectly. It is a spikes immune, paralysis abusing fighting resistant bulky Calm Mind setter with a movepool from gods and set variety making it hard to actually prepare for. Reuniclus has recently shifted into a more Calm Mind focused role due to the meta around it, but Trick Room or Life Orb 3 attacks are still potent in their own right and have their own use cases. All of this is good and all, but Reuniclus has 1 thing pushing it over the edge and which is why I do believe in it's ban: it's bulk. Let's go over some calcs, shall we?
+2 252+ Atk Dragonite Outrage vs. 252 HP / 252+ Def Reuniclus: 381-448 (89.8 - 105.6%) -- 37.5% chance to OHKO
252+ Atk Choice Band Teravolt Kyurem-Black Outrage vs. 252 HP / 252+ Def Reuniclus: 340-402 (80.1 - 94.8%) -- guaranteed 2HKO
252 SpA Choice Specs Latios Draco Meteor vs. 252 HP / 0 SpD Reuniclus: 393-463 (92.6 - 109.1%) -- 56.3% chance to OHKO
(To note, Specs Latios isn't even that used as of now over something like Colbur Berry)
Yeah. Reuniclus eats offensive threats like it's nothing. Part of the fun also comes from doing some move guessing. Yes, usually Recover and Calm Mind are a given, but the coverage this cell blob has is a pain in the ass to guess. It effectively has something that no mons of this caliber should have: options. Reuniclus is also a massive benefitter of the recent shift in how Latios is used. Latios instead of being the main man with Reun/Latios, has come to find a supporting role along side it which I find baffling. This speaks to the volume of Reuniclus itself, where the mighty Latios is used as a supportive offensive threat / para spreader to aid Reuniclus do it's job of killing everything alive.
Thundurus-Therian is very weird one to me right now. It is objectively fucking monsterous. With modest and 48 evs in Special attack, it already has the highest base special attack in the entire tiers. Combine that with 120 bp Thunders and a really good movepool, we have an extremely strong special breaker in Rain, which with Agility can win a stupid amount of endgames on it's own. All of this has been stated so many times before, where I don't wanna repeat other greats 2 million times. But yes, Thundurus-Therian is bonkers.
Here come the famous however. Under any other circumstances, Thundurus-T would have been banned ages ago, with right now, it is the only reason why Rain is still prevalent in the current meta. Without it, the entire playstyle kind of dies of. There has been experimentation with Tornadus-I recently, and while with it's benefits, like outspeeding Latios, it lacks the same way of umpf like Thundurus does. For these reasons, I would not focus on Thundurus right now, as there are more immediate matters to discuss.
On Latios and Excadrill, the arguments for an Excadrill ban are absurd to me. While absolutely busted, SD Excadrill requires ParaSpam to really make it's mark against faster teams. I also do believe it's fine to have a breaker of this caliber in the meta especially with Reuniclus still existing. Should Excadrill ever have been unbanned? I don't think so. Should it stay as of now? Yes, we need a spinner like it.
I am hesitant like most of touching Latios right now. Latios has adapted in recent years, going away from the absolute power of Specs Dracos and instead going for longevity with Colbur Berry, be it a para supporter or a Calm Mind user. I am interested to see a metagame without Latios though, ie would Latias do the defensive role Latios does right now and would there be a better metagame after it's leaving. However, we need proof for this. Finchinator discussed a potential tournament with some cash on the line with Latios banned, which I would push for right now. Until this happens, discussing a Latios ban seems like a waste of time to me, because the push for it is not simply there among top players.
In conclusion, action of order in my opinion should be banning Cloyster, banning Reuniclus and then seeing how the meta evolves after it. Look into Thundurus-T more so we have more action taken before to see if rain comes back up more after Reuniclus is banned. On the bigger changes, I would push for a tournament with Latios banned to see would the meta turn out better after. The Excadrill shouts are a waste of time to me, don't focus on that when we need it's spin in the current meta. Thank you.