Omastar - BAN - Omastar, previously a consistently underrated gem has only gotten better with the removal of Vaporeon from the tier. Vaporeon's prevalence beforehand meant that in most matches, at least those against Pokemon like Vaporeon and Lanturn, Omastar had to rely on Meteor Beam to break, hence requiring the Omastar user to predict the opposing Protect and not waste Power Herb. While this was still clearly not adequate or healthy counterplay in a lot of matches, it meant that Omastar was never a guaranteed breaker against most teams. Nowadays, with Vaporeon gone, and Lanturn's usage substantially decreased, matches come down a lot less to predicting a Protect or switch, but are instead relying on subpar methods of answering it. Teams are more reliant on unreliable checks like Vacuum Wave Toxicroak (which isn't a guaranteed OHKO if Timid), or relying on revenging with a scarfer like Togedemaru or Gourgeist-S (which aren't reliable due to how often Weak Armor activates). Lanturn is still usable for sure, but still relies on this 50% chance and additionally has to worry about the fact that Meteor Beam is no longer as required with Vaporeon gone (or Ice Beam with Virizion gone), and Earth Power is seeing use. Other random checks only have to be weakened a small amount prior to Omastar coming in / can be forced in early game with Omastar not clicking Shell Smash initially. Omastar's one saving grace coming into post-shifts was the fact its main means of setup was taking advantage of Talonflame; however, even with Talonflame gone, Omastar has very little trouble still finding opportunities to set up. Omastar is an incredibly menacing threat with a very little pool counterplay and the metagame would be substantially better off with it gone. 
Kingler - BAN - Kingler, similarly to Omastar, benefited immensely from Vaporeon's departure, but to a much larger degree. Vaporeon was a reliable wall to Kingler, and without it its defensive counterplay is astoundingly bad. Anyone who has played against Kingler in recent times knows just how stupid it can be. Teams are now reliant on Pokemon like Tangela, Poliwrath and Colbur Berry Jellicent in order to reliably answer it, when these Pokemon can often have trouble justifying their usage otherwise. While there are a variety of much softer checks and Water-resists, these are easily eliminated after minimal chip, which an Agility Kingler can easily bust through late game and claim the win. Kingler is just too powerful for the current metagame, and its continued existence in PU does not benefit the tier whatsoever. 
Clawitzer - BAN - Although Clawitzer is undeniably very slow and is unable to switch into a myriad of common threats, it is in my eyes too much for the metagame to handle. Clawitzer's power is insane, there is not a single Pokemon in the metagame that is not 2HKOd by it, while the majority is OHKOd. It is indeed limited by the fact it requires Choice Specs in order to net a lot of important OHKOs but even then opposing teams become reliant on prediction in order to deal with it. Unlike similar slow nukes Exeggutor-A and Drampa, Clawitzer's STAB is great. Water has almost no common immunities and can be easily spammed off a very high special attack stat. Exceptions to this rule include Toxicroak which is OHKOd by Dragon Pulse and Jellicent which is OHKOd by Dark Pulse. Mega Launcher allows all of its attacks to be incredibly threatening. There is no reliable switch-in to this Pokemon. Balance teams are frequently finding themselves using Protect on any Pokemon that allows Clawitzer to come in as a means of mitigating how much it can do against you, which is well, unhealthy. I am incredibly hopeful that Clawitzer will be removed from the tier.
Toxicroak - DNB - I don't see Toxicroak as broken. It's still a potent sweeper and wallbreaker, and of course is a top-tier threat; but considering how its defensive counterplay has remained virtually the same, how rarely teams will naturally just lack a check for it, it would feel wrong for me to support removing this Pokemon from the tier. It struggles immensely from its 4MSS, if it had one more slot, or wasn't required to run Vacuum Wave for the omnipresent Omastar, it would at least have much better breaking power, but as it stands, it can often find itself struggling to wallbreak, at least to the extent in which I'd find it unhealthy. It's something I'd potentially support a suspect test on in the future if metagame trends were to continue to favour it, but at the moment it is definitely not quickban worthy in the current PU metagame.
Ribombee - DNB - Ribombee, in my experience while a potent threat, has enough viable counterplay in the current metagame to justify its remaining in the tier. The prevalence of Pokemon like specially defensive Togedemaru, Silvally-Steel, Gigalith, Charizard, Garbodor in many cases and even Stunfisk-G prevent it from in my eyes being too much for the tier. Its relative frailty and lack of set up opportunities are also incredibly notable, as in many games it will struggle to get off a single Quiver Dance or do any meaningful wallbreaking. Choice Specs sets are also prominent, but neither, nor both in conjunction are problematic enough to the extent that I'd support a quickban on it.