Omastar: Ban. In the present metagame, checking all relevant offensive threats is borderline impossible, and in this kind of metagame I find mons like Omastar especially concerning, since trying to account for it results in needing very specific forms of counterplay that heavily restrict you in the builder, often leaving you weak to other top offensive threats. Because Omastar is a mon that only needs 1 free turn to win against teams that do not have reliable counterplay - of which, again, there is very little - you cannot concede the weakness and just aim to outplay the subpar matchup, as a free turn for Omastar means not that you have to sack a mon but that you outright lose the game. What results, of course, is a meta in which Omastar does not sweep teams often and therefore does not appear overtly broken, but only because its huge threat level warps the meta around itself. I think it is necessary to get rid of this threat to give people some breathing room in the builder, as the awkward team constructions I and other builders have been working with for the past few weeks have left the meta in a state of an extreme matchup-dependence I do not deem competitive. Finally I would like to mention dual screens briefly, as screens HO fixes a lot of Omastar's common troubles and turns it into much more of an overtly broken threat. After all, viable defensive counterplay is incredibly rare and most teams rely on revenge killing it with Scarf Toge or certain priority moves, but these suddenly need a lot of chip to deal with Omastar if it's behind screens. 
Kingler: Ban. Although it lacks a crazy move like Shell Smash, I have found that Kingler often still manages to serve as a mon that can just outright win if it gets 1 free turn to click Agility. Liquidation/Body Slam/Knock Off is great coverage in this meta thanks to Kingler's massive power with Sheer Force + Life Orb, and especially offensive teams struggle to deal with it after an Agility because a typical Water resist like Whimsicott is frail enough to drop to Body Slam after fairly minor chip (and chip on Whimsi is not hard to get because it usually needs to check a lot), while something like Heliolisk just outright dies. Any viable Scarfer other than Heliolisk also fails to outspeed it, making it even more difficult to check for offense than Omastar. Balance teams tend to be able to fit more things that can eat a hit or two - i.e. Lanturn, Guzzlord, Druddigon - but at the same time, such teams of course also give Kingler more opportunity to come in and break, and its more viable and splashable checks tend to lack durability. It's gotten to a point that I have considered defensive Tsareena and Leafeon just to be able to check Kingler reliably throughout a game, and trust me, these are not fantastic sets and will open your tesm up to other issues. One might argue that checks like these, or maybe more notably Tangela or Ferroseed, could start seeing more usage in order to account for Kingler and that this is just a natural progression for the meta, but here I recall Kingler's presence in SM PU and its ability to adapt to any counterplay that may arise thanks to its fantastic offensive movepool - even Tangela isn't safe because 2 Ice Beams or Knock into Ice Beam is a 2HKO. As a result, I don't see Kingler as capable of ever being a healthy presence in the meta with the possible counterplay currently available to us, at best being a mon your team can check under the condition that it runs the wrong coverage moves. Moreover, even if this were not to be an issue, this does not fix the problems more offensive teams have with Kingler. It's regrettable because I love using Kingler, but it has to go.
Clawitzer: Ban. Of the mons I voted ban on I'm the most on the fence with regard to this one. It is not entirely wrong to say that it is just another strong but slowish breaker akin to Eggy-A or Aggron, both of which happen to sport much stronger STAB moves than Clawitzer to boot. However, I believe that there are a few things that set Clawitzer apart from the rest. The first factor is that the amount of things it can exploit in the meta is actually rather great. Looking at the defensive metagame, most of it can be exploited by Clawitzer due to its lack of weaknesses to their STABs and its fantastic coverage forcing just about anything out. Bulky Grounds, bulky Rocks, bulky Ghosts, bulky Poisons, Druddigon, Wish Toge without Zing Zap, and Charizard without Hurricane (bad move btw) is just a non-exhaustive list of things that Clawitzer can force out and eat a couple of hits from if needed. Finding opportunities to get Clawitzer in on these mons is not particularly difficult either, as U-Turn bots like Passimian often force these types of slow defensive mons in. The other element that makes the pistol shrimp a bigger problem than other breakers is the breadth of its coverage. Thanks to its ability, it can choose to run a 4-pulse moveset where every move hits like a STAB move, meaning that A: balance teams and offenses with an exploitable mon need reliable resistances to all of Water/Fighting/Dark/Dragon to prevent it from just spamming one of its moves for massive damage whenever it's in, and B: since all its moves are roughly the same strength, there is no "obvious" move for it to click and trying to predict against it feels like a roulette. One might contend with regard to point A that you generally need resists for all these types and that a lot of resists to these types are rather good in the current meta, so I would like to elaborate a bit further. First, anything short of an immunity or a bulky resist with recovery is often inadequate for these moves, as things like Whimsicott and Toxicroak - the former is immune to 2 and resists the other 2, the latter is a rare Water immunity that also resists Dark and Fighting - are still frail enough to get 2HKO'd by resisted hits. Against teams that utilize mons like these to check Clawitzer, it is often very easy to spam Dark Pulse, as it has no immunities and has few viable bulky resists - and of course most of the bulky resists that do exist are weak to other moves or easily worn down. Moreover, the few checks with recovery it does have - Aromatisse comes to mind - are furthermore rather passive and exploitable compared to the checks to other powerful breakers. This blurb is already getting way too long so to wrap up: Clawitzer essentially forces very particular team structures for balance teams to reliably deal with it, as there typically will always be something it can exploit on a team and none of its individual checks are very reliable and/or durable. The result of such a constraint on teambuilding obviously means that in order to account for Clawitzer, your team necessarily will be opened up to a slew of other weaknesses, so in order to make consistent teambuilding possible in this tier I believe it has to go.
Toxicroak: DNB. I have been on the fence with regard to Toxicroak for a while now and I'm not entirely convinced we won't have to ban it eventually, but presently I'm not inclined to vote ban. The main issue with Toxicroak is the fact that between its versatility in sets and great coverage, you're never truly prepared for it, but in the current meta the versatility aspect has been much less present as Toxicroak is often forced to run NP + Vacuum Wave in order to prevent teams from losing to Omastar, leaving it checked defensively by such things as Garbodor, bulky Grounds not named Palossand, and strangely even Gigalith. Therefore I don't think it is broken currently, and it is even a somewhat healthy presence as it compresses a lot of roles that may be difficult to fit on a team otherwise (Water immune, Tspike absorber, Scrafty check, emergency revenge killer etc), but this may change once it's more free to start running Focus Blast and physical sets again. To be continued.
Ribombee: DNB. While Ribombee can feel hard to deal with, especially when your main check if something like Scarf Toge, I believe this is more symptomatic of the meta than a problem with Ribombee itself. Checks like Togedemaru, Gigalith, and Charizard are all great mons in this meta and insofar as they get pressured too much throughout the game to check QD consistently, this is moreso an effect of them having to check too much throughout a game to stay healthy - and in the case of Togedemaru, often being forced to run the easily worn down Scarf set instead of Wish because Omastar exists. Bee in and of itself is rather frail, not incredibly strong, and generally manageable in a balanced meta, so it can stay.